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A CONSTRUCTIVE METHOD 
m HISTOLOGY 



BASED UPON THE TUBE PLAN OF STRUC- 
TURE OF THE ANIMAL BODY WITH CASE 
OF MODELS FOR DEMONSTRATION 



BY 

J. S. FOOTE, M.D. 

(I 

.OGY AND PATHOLOGY IN THE MEDI 
CREIGHTON UNIVERSITY, OMAHA, NEBRASKA 



(I 
PROFESSOR OF HISTOLOGY AND PATHOLOGY IN THE MEDICAL DEPARTMENT OF 



PUBLISHED BY 

F. L. BRADBUEY 

NAUGATUCK, CONN. 

1907 






lUSAARYofSONeRESS 
Two Copies Received 
FEB 20 1907 



Oopyrleht Entry 



,SS A XXe., No. 



eoFY 



Copyright, 1905 
By JajNies Stephen Foote, M.D. 



PRE«;S OF 

The New era printing Company 
Lancaster, Pa. 



PREFACE. 

In presenting a Constructive Method in Histology the writer is con- 
scious of a somewhat radical departure from the usual plan followed by 
books upon the subject. It seems, therefore, desirable to explain in 
some detail the principal reasons for diverging from the methods ordi- 
narily adopted by most authors. Experience in teaching leads one to 
the conviction that those beginning the study of histology find more or 
less difficulty in forming a clea^ conception of the subject and are quite 
likely to fall into the habit of committing to memory descriptions of 
structures which they either have not seen or can not see without some 
experience in gross anatomy and in the use of the microscope. 

In some cases they have no knowledge which enables them to assim- 
ilate the new and complex ideas to which they are abruptly introduced. 
Under these circumstances, to present a series of isolated facts which 
have little or no apparent connection with the facts of allied subjects, 
is to violate a fundamental principle of the mind's development. It has 
long been recognized by educators that such facts are mere symbols pos- 
sessing no impulsive power, and hence producing no lasting results. 
The mind finds satisfaction in the organization of its ideas. There is 
a certain intellectual pleasure and profit in following the orderly and 
progressive development of a subject which takes as its point of de- 
parture some fact or group of facts which fall within the experience 
of all. 

Histology is one of the fundamental branches of medicine and is use- 
less to the majority of medical students unless it has some definite bear- 
ing upon medicine. As a rule, it is not easily committed to memory 
because its facts are not easily understood. In those cases which are 
successful on account of persistent application, the knowledge acquired 
exhibits a vague and devitalizing character which confuses the student 
and leads him into error or indifference. The subject is usually taught 
during the freshman year at a time when the anatomist is teaching 
osteology and myology ; consequently, when the histologist takes up the 

iii 



IV PREFACE. 

tissues and refers to their part in the construction of the various viscera, 
the student may not even know what or where those viscera are and 
receives no direct information from his anatomical course. It is ahnost 
useless, for example, for a teacher to describe transitional epithelium as 
it occurs in the pelvis of the kidney, ureters and bladder if the student 
does not know the locations or purposes of these organs. He may take 
the trouble to enlighten himself on this point, or may, instead, commit 
facts to memory only to forget them more easily than he committed them. 
It can not be expected that he knows really anything about the viscera 
if he has never seen them or heard them described. On account of this 
fact, a few plates of gross anatomy are introduced to enable the student 
to form some conception of the locations and relative positions of the 
more important viscera, the structures of which he is expected to know, 
perhaps, before dissection or even simple observation affords him that 
information. The most important reason, therefore, for this departure 
from the customary course in histology, is to employ the constructive 
faculties of the mind as they are based upon observation instead of its 
purely memorizing capacities. If we believe that the mind is funda- 
mentally an activity rather than an organ for receiving and recording 
impressions, we shall readily agree that its constructive powers are of 
primary importance where a mechanism is concerned. It is only when 
the mind is employing its native capabilities in the solution of problems 
which it has formulated for itself, and in the elaboration of which all its 
energies are voluntarily enlisted, that knowledge of permanent value can 
be attained. Such intellectual labor is far removed from that of merely 
receptive or memorizing processes, and experience shows that knowledge 
thus acquired becomes an integral part of the mind's capital. This work 
is intended to provide, in concrete form, for the constructive activity of 
the normal mind. It consists of two parts, viz : a descriptive text setting 
forth the constructive method based upon tube formations, and a case 
containing building models and the outlines according to which the 
organs are constructed. The tube is taken as a fundamental, structural 
and functional unit of visceral formation. It has motor and non-motor 
characteristics which are believed to be extremely important as guides 
in the formative plan of visceral structures. The value of some sort of 
manual work in connection with mental activity is conceded by most 



PREFACE. V 

educators. By means of tlie accompanying models students may learn 
to construct any tube of the animal body and thus may find, not only a 
medium for motor expressions, but also a method of clarifying and 
classifying facts already partially grasped. Moreover the constructive 
process tends to produce concrete results which are capable of practical 
application. The problem of what to learn and what not to learn con- 
fronts the student in every branch of study. Not possessing a judgment 
trained in the distinction of values, he must select from all available 
sources what his previous experience leads him to believe is important 
and omit the remainder. Errors in judgment are frequently made and 
to this source may be traced much of that vague knowledge which is 
devoid of all dynamic power. In the construction of any complex 
mechanism the builder usually follows some design more or less com- 
pletely developed and the finished structure is a visible interpretation of 
that design. As a result the builder is not burdened with materials 
which he does not use and the structure is not rendered worthless by rea- 
son of the extraneous matter which has been added to it without refer- 
ence to a rational design. The constructive method is believed, there- 
fore, to be the most satisfactory method of approaching the subject of 
histology. The animal body is a mechanism and most of the organs of 
this mechanism are tubes which are composed of various tissues. These 
tissues are arranged according to a particular design which best serves 
the requirements of the tube. If we have the tissues and know the design 
we can construct any organ of the body. This is the object of the accom- 
panying models. They all have the same curve and are intended to 
represent cross-sections of tubular structures. The circles employed in 
their formation have the same diameters. The same curve is employed 
for both the large and small tubes in order that the number of models 
may not be in excess of convenience as building materials. Upon them 
are printed, somewhat diagrammatically, the different tissues and their 
varieties— epithelial structures in pink, muscular in red and connective 
tissues in white. The nuclei in all cases are blue. These colors are 
intended to represent the hsematoxylin and eosin stains. The word 
outlines which are printed upon the inside leaves of the case form the 
design or plan according to which the organs are built. The numbers 
at the left of the models are for the convenience of the beginner. They 



VI PREFACE. 

may be disregarded as soon as the tissues are familiar. The numbers 
beneath and at the right of the word outlines are model numbers which 
may also be disregarded as soon as the tissues are known. The details 
should be worked out in the laboratory under the direction of the teacher. 
It is essential that students have a knowledge of tissues and cells before 
the constructive process begins. This method then, departs from the 
customary at that part of the histological course, which is concerned with 
the study of organs or viscera. This work is not intended as a complete 
text-book of histology for there are many very excellent books already. 
It is designed as a teaching method based upon simple observation and a 
teacher's experience; and by its use both teacher and student may be 
more closely brought together, being engaged in the actual construction 
of something of common interest. If teacher and student can actually 
build a mechanism by means of materials which are in their possession, 
the completed structure really means much more than a simple mental 
act could possibly accomplish. Furthermore, the simple act of construc- 
tion develops the physiological reasons for histological structures and 
thus correlates the whole. The plates used have been taken from well 
known text-book sources, re-drawn, and adapted to tube structures. 
This method, employed as a means to an end, is thought to constitute a 
useful scheme for the acquisition of a knowledge of a subject somewhat 
difficult in character. It is not supposed that the book, outlines and 
models are free from errors. On the contrary the nature of the subject 
is such that errors are almost inevitable. However a new method of 
teaching and of learning histology is presented, the application of which 

will determine its value. 

J. S. FooTE, M.D. 

Creighton Medical College, 
Omaha, Nebraska, 1906. 



CONTENTS. 



PART I. 



SECTION 1. 

Cells and Tissues as Building Materials • • . • 1 

General Outline of the Animal Body, 3, 4, 5 ; The Cell, 7 ; Cell Membrane, 7 ; 
Spongioplasm and Hyaloplasm, 8 ; Attraction Sphere and Centrosome, 9 ; 
Plastids, 9; Vacuoles, 9; Metaplasm, 10; Nucleus, 10; Nuclear Membrane, 
10; Chromatin, 10; Achromatin, 11; Nucleolus, 11; Net Knots, 11; Linin, 
11; Cell Division, 12; Cause of Cell Division, 13; Sex— a Substitute for 
Solar Agencies and Vegetation in the Formation of New Protoplasm, 14; 
Varieties of Cell Division, 14; Karyokinesis, 15; Amitosis, 16; Binary 
Fission, 16; Spore Formation, 18; Budding, 18; Stages of Karyokinesis, 
18, 19 ; Tissue Genesis, 21 ; Systems of the Body, 22 ; Tissues, 22 ; Epithelial 
Tissue — Classification, Varieties, Description, Location, 24; Special Epi- 
thelial Cells— Varieties, Description, Location, 26; Special Connective 
Tissue Cells — Varieties, Description, Location, 28 ; Connective Tissues — 
Varieties, Description, Location, 30, 32, 34, 36, 37; Blood, 38; Muscle- 
Varieties, Description, Location, 40; Nervous Tissue, 42; Nerve Termina- 
tions, 44. 

SECTION 2. 

Constructive Method Based upon the Tube Plan of Structure of the 

Animal Body 46 

The Tube as a Structural and Functional Unit, 47 ; Plan of Tube Arrange- 
ment, 48; Formation of Tubes, 49-59; Models Numbered and Described, 
60, 61 ; Arrangement of Tubes in Five Classes, 61 ; Outlines of Formation 
of Tubes, 62 ; Outlines, 62 ; Mechanics, 64 ; Non-Motor and Motor Tubes, 64 ; 
Outline of Non-Motor and Motor Tubes, 67; Construction of Tubular 
Organs by Models, 68, 69 ; One-Layer Tubes— Non-Motor, 69 ; One-Coated 
Tubes— Non-Motor and Ciliary Motor, 72; Outline of External and Middle 
Ear, 75; Outline of Internal Ear, 76, 77; Two-Coated Tubes— Ciliary Motor, 
80; Three-Coated Tubes— Muscular Motor and Muscular- Ciliary Motor, 81; 

vii 



vin CONTENTS. 

Organs which Belong to the Three-Coated Tubes, 82; Outline of the Eye- 
ball, 89 ; Outline of the Iris, 90 ; Outline of the Retina, 91 ; Outline of Other 
Parts of the Eye, 92 ; Four-Coated Tube— Muscular Motor, 95 ; Description 
of the Four Coats— Connective, Muscular, 95; Subepithelial and Epithelial, 
96; Tissues as Building Materials, 97; Outline of Three Tissues Seen in 
Tube Structures, 99, 100 ; Outline of the Five Circulations, 101 ; Outline of 
the Lymphatic System, 102; Location of Tissues in Tubular Organs, 107; 
Outline of the Functions of Tissues, 108; Contents of Tubes Govern Their 
Motor Structures, 108 ; Organs which Apparently do not Conform to the 
Tube Plan of Structure, 111 ; Outline of Cerebrum, 112, 113 ; Outline of 
the Crura Cerebri and Pons Varolii, 114; Outline of Medulla Oblongata, 
115, 116 ; Outline of Cerebellum, 117 ; Outline of Spinal Cord, 118 ; Outline 
of Pituitary Body, Pineal Gland and Olfactory Lobe, 119 ; Outline of 
Spleen, Adrenals, Thymus and Tonsil, 120; Description of the Constructive 
Diagram, 126 ; Conclusions Drawn from the Constructive Diagram, 127, 128. 

SECTION 3. 

Technique— Preparation of Normal Tissues 131 

Processes Described — Killing, Fixing, Hardening, Decalcification, 132; 
Dehydration, Infiltration, Embedding, Cutting, Staining, 133; Mounting, 
134; Outline of Fixing and Hardening Formulae, 135; Outline of Decalci- 
fication, Dehydration and Infiltration, 136 ; Outline of Embedding and Cut- 
ting Processes, 137; Outline of preserving Sections, Fixing Paraffin and 
Celloidin Sections, Stains, 138; Outline of Stains, 139-142; Outline of 
Blood Smears and Fixing Methods, 142; Outline of Clearing Agents, 143; 
The Double Stain, 143; Outline of the parts of the Microscope, 144. 

PART II. 

A Case op Models with Architective Outlines for the Construction 
of Organs According to the Constructive Method 



ILLUSTRATIONS. 



Plate I. The Cell. The Four Theories of Cytoplasmic Structure 6 

Plate II. Diagrams of Mitosis 17 

Plate III. Diagrams of Fertilization and Tissue Genesis 20 

Plate IV. Different Varieties of Epithelium 25 

Plate V. Special Forms of Epithelium 27 

Plate VI. Connective Tissue Cells. Blood 29 

Plate VII. The Varieties of Connective Tissue 31 

Plate VIII. Cross Section of an Entire Bone 33 

Plate IX. Tooth 35 

Plate X. The Varieties of Muscle 39 

Plate XI. Various Types of Nerve Cells, Neuron, Neuroglia 41 

Plate XII. Nerve Terminations 43 

Plate Xlla. The Five Classes of Tubes Constructed by Tissue Additions 51 

Plate XIII. Connective Tissues as Coats of Organs 53 

Plate XIV. Muscular Tissues as Coats of Organs 54 

Plate XV. Epithelial Coats of Organs 55 

Plate XVI. Epithelial Coats of Organs 56 

Plate XVII. Epithelial Coats of Organs 57 

Plate XVIII. Neuro-Epithelium, Epithelium, Connective Tissue Coats 

of Organs 58 

Plate XIX. Connective Tissue and Neuro-Epithelial Structures 59 

Plate XX. Outlines Applied to Structural Formation of the Five Tube 

Classes 63 

Plate XXI. A Portion of the Capillary Circulation 70 

Plate XXII. Thirty-one One-Coated Tubes in One, Showing Layers in 

Common 71 

Plate XXIII. Four One-Coated Ciliary-Motor Tubes in One, Showing 

Layers in Common 72 

Plate XXIV. Types of Secreting Glands, One-Coated Tubes— Non-Motor 73 
Plate XXV. Membranous Labyrinth of Ear— One-Coated Tube— Non- 
Motor 77 

Plate XXVI. Diagram Showing Kidney Tube and Its Connection with 

Circulation 78 

Plate XXVII. Larynx, Trachea, Bronchi. Two- and Three-Coated Tubes 79 

ix 



X ILLUSTRATIONS. 

Plate XXYIII. Microscopic Section of Trachea and Large Bronchi .... 80 

Plate XXIX. Vagina, Uterus, Fallopian Tubes, Ovaries 81 

Plate XXX. Diagram of the Circulations 83 

Plate XXXI. Kidneys, Ureters and Bladder 84 

Plate XXXII. Vas Deferens, Epididymis, Testicle 85 

Plate XXXIII. Twelve Three-Coated Tubes in One, Showing Coats Com- 
mon to Them All 86 

Plate XXXIV. Seven Three-Coated Tubes in One, Showing Coats Com- 
mon to Them All 87 

Plate XXXV. Alimentary Canal 93 

Plate XXXVI. Eight Parts of the Alimentary Canal 94 

Plate XXXVIa. Systemic Circulation 103 

Plate XXXVII. Pulmonary Circulation 104 

Plate XXXVIII. Portal Circulation 105 

Plate XXXIX. Renal Circulation 106 

Plate XL. Cerebrum and Spinal Cord 121 

Plate XLI. Spleen and Thymus 123 

Plate XLIL Adrenal, Lymph Node 124 

Plx^te. Constructive Diagram 128a 

Plate of Microscope 145 



PART I 

SECTION I 
CELLS AND TISSUES AS BUILDING MATERIALS 



GENERAL OUTLINE. 

Observation with tlie naked eye shows one that a living animal eats, 
breathes, moves, expels waste matters, reproduces its kind, bleeds when 
cut, smells, tastes, feels, hears and sees. From this observation it is 
evident that it must have certain definite parts which are set aside for 
these purposes. These parts, called systems, are the general divisions 
of the body. They are named according to the various functions which 
they perform, as— digestive, respiratory, muscular, urinary, genital, 
circulatory, sensory, etc. Observation by dissection shows that all of 
these systems are composed of smaller parts. These are called organs. 
They have received their names from anatomical and physiological 
observers of remote dates and do not appear to present any family rela- 
tionship. Naked eye observation terminates here. Investigation, which 
is then possible by means of the microscope, shows that the organs are 
composed of smaller parts. These are called tissues — four in number. 
Further investigation shows that the tissues are composed of smaller 
parts called cells, and intercellular substances. The cells are found to 
be composed of still smaller parts which, at the present time, remain as 
the ultimate structures of the animal body. This method of analysis 
affords us a general view of the constituent parts of the body and also 
of the body as a whole and is presented in the outline which follows. 
The historical and histological structures of the cell are indicated in 
plate I. which follows the outline. 



A COySTRUCTIVE METHOD IN HISTOLOGY. 



OUTLINE 


OF THE GENERAL STRUCTURES OF THE 


ANIMAL BODY. 




Systems. 


" -I 
Okgans. 


No. OF 
Tissues. 


Tissues. 


Varieties of Tissues. 




1. Heart.* 










Pavement, 




1. Circulatory.* ■ 


2. Blood vessels. 

3. Capillaries. 

4. Lymphalics. 

1. Mouth. 

2. Salivary glands. 

3. Tongue. 








1. Simple. 


Squamous, 
Tessellated, 
Scaly or 
endothelium. 

Glandular, 
Polygonal, 




2. Digestive. < 


4. QSsoj)hagus. 

5. Stomach. 










Polyhedral. 






6. Intestines. 




1. Epithelium. 


. 




Columnar, 






7. Liver. 










Cylindrical, 






8. Pancreas. 










Cubical, 
Ciliatea. 






1. Larynx. 












3. Respiratory. < 


2. Trachea. 

3. Bronchi. 

4. Lungs. 








Pavement, 
2. Stt^tlfied. < Sq-IJa^ 
Scaly. 


















1. Brain. 














2. Spinal cord. 








3. Transitional. -{ Stratified. 




4. Nervous. •< 


3. Ganglia. 

4. Sympathetic, 

Centro-spinal 
Nerves. 

1. Skeletal. 










5. Muscular. 


2. Visceral. 

3. Heart. 










1. Long bones. 








Animal. ■ 


6. Osseous. H 


2. Flat bones. 

3. Irregular bones. 

1. 67e/-M,9. 


Four. 










2. Fallopian tubes. 














3. Ovaries. 








1. Blood. 






4. Labia majora. 








2. White fibrous. 






5. Labia minora. 








3. Yellow elastic. 






6. Clitoris. 








4. Areolar. 






7. Peni5. 








5. Mucous or embryonic. 




7. Genital. 


8. Testicle. 

9. Fasa efferentia. 

10. Epididymis. 

11. Fflw deferens. 

12. Vesiculae semin. 

13. Prostate gland. 




2. Connective 


1 


6. Adipose. 

7. Lymphoid, adenoid, retiform, 

reticular 

8. Cartilage. 

9. Bone. 

10. Neuroglia. 






14. Coivpe7-'s gland. 












15, Littre's glands. 










I 


1. Kidneys. 










8. Urinary. -< 


2. Ureters. 

3. Bladder. 










9. Sensory. ^ 


Eye, ear, nose and 
appendages. 

1. Lymph node. 

2. Thymus.thyroid. 

3. Adrenals. 




3. Muscular. 


1 Striped voluntary, 
■J Striped involuntary, 
1 Un striped involuntary. 

1 Neuron. 
-< Nerve cells, fibres. 




10. Not Classified.^ 


4. Spleen. 




4, Nervous. 






5. Pineal gland. 






1 Neuroglia. 






6. Pituitary body. 












7. Coccygeal gland. 









* V/ords in italics indicate tube systems and organs. 



GENERAL OUTLINE. 



OUTLINE OF THE GENERAL STRUCTURES OF THE ANIMAL BODY. 



Structure 

OF A 

Tissue. 



1. Cells. 



2. Base. 



General. 



Structure of a Cell. 

Minute. 



1. Cell membrane. 



Description of Minute Structures. 



Product of cell cytoplasm surrounding the cell. Living 
or lifeless. 



V 



Fibrillar, alveolar, or granular mesbwork — active or 
passive. 



J Structureless, labile, ground substance in the meshes- 



2. Spongioplasm 

3. Hyaloplasm. ^ ^^^^ ^^ metaplasmic deposits. 

4 Atfrnotinn snhpre J Radiating, astral, protoplasmic substance active in cell 
1. Cytoplasm. -J *• -^viiracuou bpnere. ^ division. 

5. Ceutrosome. 



6. Plastids. 

7. Vacuoles. 

8. Metaplasm. 



J Single or multiple granules within the attraction sphere. 
1 Dynamic center of a cell. 



j Substances which by growth and division become starch, 
1 chlorophyll or pigment. 



2. Nucleus. 



■{ Spaces occupied by a liquid. 

-! Passive granules, either foods or waste products of cells. 

1. Nuclear membrane. -{ Extended chromatin layer surrounding the nucleus. 

2. Chromatin. 

3. Achromatin. -{ Colorless liquid occupying nuclear network. 



J Vital, staining substance, causing cell division and cell 
1 phenomena. 



A ^c„r^ar^„c J Small bodies which stain like cytoplasm, the function 

4. rsucieoius. ^ of which is not understood. 

5. Chromatin knots. -{ Small aggregations of chromatin. 

(. T • • J Reticular base which stains like cytoplasm, supporting 

D. x.mm. -<j nuclear structures. 



Structure of Base or Intercellular Substance. 



It occurs between cells as a base and may be either cement, fibres or both. 

There are reasons for supposing that between all cells adjacent to each other there is an organic con- 
tinuity in tlie form of intercellular bridges. 




— Net Knots. 
Chromatin- 

vacuole. 

H^a(o^(asm. 



THE CELL 



PLATE I. 



HiSTOKICAX, A]SD StRUCTTBAL DIAGRAM. 

The four theories of CYtoplasmic structure and the various parts of which the cell is composed. 



THE CELL. 

The cell is a chemical and mechanical unit of structure, the phe- 
nomena of which depend upon the peculiar manner in which the terminal 
is constructed. It is composed of the chemical elements, C, H, 0, N, S, 
P, Na, K, Ca, Mg, and Fe, arranged in some definite form, which is 
known as protoplasm. Within protoplasm certain chemical changes are 
constantly in progress with the liberation of energy— the direction of the 
energy depending upon the cell mechanism. As the blood, the common 
source of chemical supply, is always constant in its chemical constitu- 
ents and always contains all the elements of protoplasm, certain varia- 
tions in mechanism must occur in different cells in order to account for 
the differences in cell products and activities. Thus cells may secrete 
milk, bile, ptyalin or mucus, may excrete urea or water, may shorten and 
lengthen— causing motion, may divide and construct new tissue, or may 
liberate accumulated energy at the moment of irritation. They are not 
homogeneous in structure; but are composed of many parts— the func- 
tions of these parts added together forming the function of the cell. 
The cell is a complex structure. It always has two parts— cytoplasm 
and nucleus. The cytoplasm may comprise a limiting or cell membrane, 
spongioplasm, hyaloplasm, plastids, vacuoles, and metaplasm. The 
nucleus may contain a nuclear membrane, chromatin, achromatin, nu- 
cleolus, chromatin knots and linin. This makes a heterogeneous struc- 
ture exceedingly intricate in character. All of the parts above men- 
tioned are not found in every cell ; but every cell contains many of them. 
No two of them are precisely alike and hence do not have exactly the 
same office : so that if a variation in the possession of the parts is pos- 
sible, a variety of functions must be allowed. A brief consideration of 
these various structures is necessary. 

Cell Membrane.— Gjio-plsism is almost midway between a liquid and 
a solid, perhaps it is just within the limits of a solid. The outer limiting 
membrane is the analogue of the slightly condensed ectosarc of the one 
celled animals. An enclosing membrane of varying density would be 

7 



8 A CO^STRUCTITE METHOD IN HISTOLOGY. 

advantageous to the semi-solid protoplasm or cytoplasm as it is well 
adapted to the purposes of protection, osmosis and retention of the labile 
parts within. It would vary in density according to the movable or fixed 
character of the cell ; so that in a wandering cell the least degree of den- 
sity would be essential while in a fixed or vegetable cell the highest degree 
would be required and between these extremes all degrees would be found 
according to the nature of the cell. 

Spongioplasm and Hyalo plasm.— The division of cytoplasm into two 
parts is the outcome of many observations made upon many cells. Dur- 
ing the early period of microscopical experience cytoplasm was generally 
considered as a homogeneous structure and within it was located the 
nucleus. Improved microscopes and technique however enabled differ- 
ent observers to distinguish two parts which have received many names 
—among them spongioplasm and hyaloplasm. By spongioplasm, is 
understood a reticular structure which stains with some aniline dyes and 
by hyaloplasm the labile, unstainable contents of the meshes of the 
spongioplasm. The structure of cytoplasm has been subject to several 
modifications according to different observers and to the character of 
the cell examined. Flemming described it as composed of a delicate net- 
work of fibrils enclosing the structureless hyaloplasm. The net-work 
was the spongioplasm. Altmann described it as made up of small gran- 
ules capable of nutrition, growth and division. This theory made cyto- 
plasm a cooperative community of individual parts, the combined func- 
tions of which established the function of the cell. Biitschli described 
it as alveolar in character, which condition was due to the presence of 
minute globules. He made emulsions of olive oil and found that the 
structure and appearance of the emulsion resembled the structure and 
appearance of cytoplasm so closely that in most instances it was difficult 
to distinguish between them. Later observation has resulted in the con- 
clusion that cytoplasm may be homogeneous, granular, fibrillar or 
alveolar according to the age of the cell and these different structures 
may be associated with graded processes of cell activity. Within the 
cytoplasm are found other bodies which are sufficiently permanent to be 
regarded as essential to the cell. Something of the importance of these 
bodies may be understood from the following descriptions of them. 



THE CELL. 9 

Attraction Sphere and Centra some. —The attraction sphere is a 
spherical body usually situated in the cytoplasm, sometimes in the 
nucleus, consisting of a circumferential and central portion. If the 
sphere is cut by a plane passing through its center, the intersection of the 
plane and surface of the sphere is marked by a circle of minute bodies 
called microsomes from which astral rays extend. The central part has 
either a finely reticular structure and varies in dimensions according to 
the dividing activity of the cell or a radial structure proceeding from the 
central granules. The reticular structure may give place to the radial 
as the process of cell division with which the body is associated advances. 
In some cases the attraction sphere entirely disappears during cell divi- 
sion and hence it cannot be considered as an indispensable body. 

C entrosome.— ^iihm the attraction sphere is the centrosome which 
is composed of one, two or more granules. This body has the power to 
express its individual capacity by the properties of nutrition, growth, 
and reproduction and accordingly behaves in these respects as a perma- 
nent and essential part of the cell. ^Hien active it initiates the process 
of cell division and hence has been called the dynamic center of the cell. 
In this capacity it has been thought by some to be the vehicle which con- 
veys a chemical substance which excites to activity the preliminary 
changes which start the process of cell division. But it is not always 
present and hence cannot be considered as the controlling cause of such 
an important act in cell life. 

Plastids.—The^Q small bodies appear in the cytoplasm and exhibit 
the properties of nutrition, growth and division like permanent 
structures. In embryonic cells they are small and colorless ; but acquire 
new capacities as they develop in the growing cell. Some of them estab- 
lish the process of chlorophyll formation and are called chloroplastids : 
others the process of starch formation and are called amyloplastids and 
still others, the process of pigment formation and are called chromo- 
plastids. They seem to preside over the formation of coloring matters 
or pigments which have a fundamental importance in the vegetable king- 
dom. 

Vacuoles. — These are spaces filled with a liquid and are most com- 
mon in vegetable cells and in the protozoa. During the chemical 
changes taking place in metabolism small quantities of liqui(J may be 



10 A CONSTRUCTIVE METHOD IN HISTOLOGY. 

produced wHch collect in spaces, thereby enlarging and forming small 
cavities or vacuoles. In some of the protozoa the vacuoles are contrac- 
tile as though they had some part in the circulation of the nutritive 
liquids of the cell. In the higher animals the cells do not contain vacu- 
oles except in pathological conditions. 

Me^a^^a^m.— During cell metabolism small bodies, granular in char- 
acter and passive in behavior, appear in the meshes of the cytoplasm. 
These bodies are included in the term metaplasm: it is not known 
whether they are foods in reserve or waste matter. Cytoplasm then is 
a body having a fundamental structure which contains several other 
bodies dependent or independent, active or passive in character. Its 
wide departure from a homogeneous formation gives it a great range in 
function. It seems to be a cooperative society of individuals each one 
of which is engaged in the performance of a part for the better condition 
of the whole. 

Nucleus,— The nucleus is a round or elongated body enclosed by the 
cytoplasm and presenting for consideration various structures. It 
makes a mass of protoplasm a cell. It takes charge of anabolism or the 
constructive side of metabolism. It makes continuation of the living 
cell possible. Cytoplasm is capable of katabolism only and is able to 
continue itself until its chemical elements are exhausted, when it ceases 
to belong to living matter. The nucleus is usually single, but in a cer- 
tain few cells it is double. Increasing the number is very likely to 
change the function. 

Nuclear Memhrane.—lLhi^ structure is a thin, delicate membrane 
surrounding the nucleus. It may or may not take a stain and for this 
reason it is thought that its derivation may vary— sometimes arising 
from the cytoplasm and sometimes from the chromatin. In the latter 
case it would be a true nuclear structure ; while in the former it would 
not. Usually it disappears during the first stage of cell division by 
absorption of the chromatin and hence it may be considered in most 
cases as a part of it. It is always present in a resting cell and is evi- 
dently an indication of that condition. It forms the boundary between 
the formative and formed parts of the cell. 

Cliromatin.—Thi^ is the most important structure of the nucleus, 
)ince upon it depends cell division and continuation. Chemically it is 



THE CELL. 11 

composed of nucleinic acid and a proteid. Structurally it is composed of 
threads or granules. In a living condition it is not affected by ferments. 
It is called chromatin because it takes a stain and its staining capacity 
increases according to its activity. By its increasing amount under 
stimulation, its transverse and longitudinal cleavages, its behavior 
toward the centrosome and spindle, it becomes so arranged that its ulti- 
mate distribution into two equal parts is known as indirect cell division 
or karyokinesis. Its relation to the cell is such that by virtue of its 
chemistry it causes the element N to maintain its carbon association and 
thereby its potential position. According to some cytologists it has been 
transferred from parent to offspring, from generation to generation, 
through all the ages of living existences and hence has been the medium 
through which the characteristics of protoplasm are maintained. 

Achromatin. — This is a colorless liquid without staining capacity, 
which occupies the spaces of the nuclear network. Little is known about 
it more than that it does not take a stain. It may be a nutritive liquid, a 
waste liquid or a supporting medium which, by its liquid condition, 
allows freedom of motion on the part of the chromatin during its 
activity. 

Nucleolus.— A small, round or irregular body suspended in the 
nuclear network. There may be one or many or none in a nucleus. It 
does not seem to be necessary to the existence or continuation of any 
living part. Two varieties are described— one which stains like cyto- 
plasm and the other like chromatin. The former is the true nucleolus 
while the latter are collections of chromatin. The real nature of the true 
nucleolus is unknown. Some regard it as a reserve fund of material 
which comes into use during nuclear activity. Others consider it as a 
product of chromatin activity. 

Net Knots (Chromatin Knots). — These are small aggregations of 
chromatin produced by crossed chromatin threads ; they have, therefore, 
the same function as chromatin. 

Lmm.— This is the fine reticular network which constitutes the sup- 
porting framework of the nucleus. It appears to resemble the mesh- 
work of cytoplasm more than any other structure. It is somewhat 
granular in character and shows granules of different staining capacity. 
A difference in staining capacity indicates a chemical difference between 



12 A CONSTRUCTIVE METHOD IN HISTOLOGY. 

bodies and this is often the only obtainable distinction between proto- 
plasmic structures. The nucleus, therefore, is a collection of different 
materials enclosed by a membrane. The chief one of these is chromatin. 
As a body it presides over cell phenomena. The nuclear parts, plus the 
cytoplasmic parts, all acting in harmony constitute the cell which may 
be regarded as a community, the a:ffairs of which are governed by small 
boards of administration. 

Cell Division ok Eepkoduction. 

All living cells, vegetable and animal, divide into two or more parts. 
This act is essential to their continuation ; for if division did not occur at 
some time they would grow old and die. This remarkable behavior does 
not admit of explanation by itself. To say that cells divide from choice 
—inasmuch as the division is apparently a destructive process— is to 
grant an intelligence beyond that of the highest degree of the human 
mind. With all his courage and reasoning capabilities man, for example, 
would never dare to divide into two parts, if such an act were possible ; 
for such a division would mean certain death to him. Such a tremendous 
process or act could only be the natural result of forces persistently at 
work in order to better the condition of the creature and not within the 
power of the individual. If cells remained the same in chemical mass 
they would remain the same in the exhibition of their phenomena and 
progress would become impossible; but they do not. Metabolism, by 
virtue of which chemical elements are constantly leaving cells and new 
chemical elements of the same kind but from a different source are con- 
stantly being added, produces an almost infinite series of variations and 
renders advance not only possible but actual. A cell cannot be precisely 
the same during any two successive periods of time, however short those 
periods may be, and if the chemical income exceeds the chemical outgo 
for any stated unit of time it will increase in mass and size. This is 
growth or the process by which a molecule of living matter adds to itseK 
atomic groups of the same kind from the chemical substances of its envi- 
ronment and arranges them in forms like its own. As cells increase in 
size the relation of mass to surface will be changed and this upset in the 
ratio between mass and surface may cause division. As spherical bodies 
increase in size the cube of the mass is proportionate to the square of the 



TEE CELL. 13 

surface ; so that the volume increases mucli more rapidly than the sur- 
face. As chemical elements necessarily enter through the surface there 
comes a time when the central part receives less than the exterior and 
death follows : but just at this time division occurs, two smaller cells are 
produced and the ratio is restored to the normal. Cell division, then, is 
the certain result of growth and therefore a primitive and universal 
attribute of living matter. Cell division also limits the size of the cell 
and establishes the metazoa. The immediate cause of cell division is 
beyond detection. Chemical combinations and separations are invisible 
although an observer may be satisfied that they have occurred as he sees 
certain unmistakable results. The nuclei of cells show plainly that 
changes have taken place in the chromatin and cytoplasm during divi- 
sion and these changes present different phases of a continuous process 
which may be considered as a progressive molecular construction. 

The cause of cell division must be attributed to the chemical ele- 
ments added to the chromatin and these elements, apparently at least, 
do not always appear to have the same power. The particular form in 
which the added elements have existed seems to make some difference in 
the energy capacity of cell protoplasm. Of the two types of dividing 
cells which occur in the body, viz., tissue and germ cells, the germ cells 
exhibit the greatest capacity for energy inasmuch as they possess the 
original fund of force which is transmitted to all other cells by some 
fixed law of distribution. As tissue cells undergo metabolism the new 
chemical elements are derived from the chemical substances of their 
environment as— the proteids, carbohydrates, fats, salts and water; but 
somewhere in the anabolic side of the process a slight loss is sustained 
either on account of chemical changes in the protoplasmic mechanism or 
of variation in combining powers, and age or diminution of energy fol- 
lows. The tendency on the part of tissue cells is toward a lowered 
capacity until death and decomposition take place and the old elements 
are brought into new, living forms again by the agency of sunlight. 
During the ascent of elements from the ashes of metabolism through 
vegetation to animal protoplasm and the rise of N from an ammonia 
group to a carbon group an increased energy capacity is obtained, so 
that death and decomposition are preparatory stages of a rejuvenated 
condition— the sun acting as the lifting power. But when the elements of 



14 A COySTRUCTIVE METHOD IX HISTOLOGY. 

the chromatin of a sperm cell are added to the similar elements of the 
chromatin of a germ cell the death, decomposition and solar agencies 
seem to be abridged and a rejuvenating result is accomplished in a short 
time through the agency of this union which is known as sexual. Sex, 
then, is the chief difference between senescence and rejuvenescence in 
cell life and is a substitute for the long process involved in the death, 
decomposition and solar agencies employed to rejuvenate protoplasm. 
This may be expressed in outline as follows : 



-^^ ^ Decomposition. J y^tari^ ) Prot^Plasm. 

1 Tendency toward I <^™„i I xpw 
Age. -l Death and 4 ^^?^^ J .^ r^^y 

° 1 TiPoomm...-t.-nT, I ^^^n. 1 Protoplasm. 



Decomposition. 

If the chromatin of one tissue cell could be added to the chromatin 
of another, doubtless rejuvenescence would follow— but this is impossi- 
ble and hence the long route through death to life. Any chemical body 
undergoing chemical action loses a part of its elements and likewise a 
certain amount of energy and neither its elements nor its energy can be 
reinstated without the help of some outside force. The protoplasmic 
molecule is very large and very comjDlex and tends to run down. If one 
supposes that it contains 1,000 atoms and during its chemical actions it 
loses 100 of them the remaining molecule of 900 atoms would still be 
protoplasmic, but could not possess the same amount of energy as the 
original molecule of 1,000 atoms. Its phenomena would, also, be like 
the original but not the same. This is senescence and the fede of all 
living cells unless thwaiied by sex. 

Varieties of Cell Division. 

1. Simple or direct division or amitosis. 

2. Indirect division or mitosis or karyomitosis or karyokinesis. 
The primitive form of division as seen in the protozoa is the simple 

or direct. This may occur as a binary fission, a spore formation or a 
budding process. Spore formation and budding are modifications of 
simple binary fission. Simple or binary fission consists of the separa- 
tion of the cell into equal parts— the cleavage occurring in a longitudinal 
or transverse direction. It may occur in the active or cystic condition 



THE CELL. 15 

of the cell. The nucleus is slowly elongated, then becomes dumbbell in 
shape, then is constricted to a mere thread and finally breaks into parts, 
each one of which becomes the new nucleus of a new cell. Then the divi- 
sion of the surrounding protoplasm follows. This is the common method 
of division in all protozoa except the Sporozoa which divide by spore 
formation. But this is simple division modified rather than a distinct 
method of division. Some unicellular animals enclose themselves in a 
cystic envelope which is a means of defense against surrounding condi- 
tions unfavorable in their nature. In this state the nucleus may divide 
into two, four, eight, sixteen or more parts in the same manner as it does 
when in an active state. By a continuation of the process a vast number 
of parts may be produced each one of which is extremely small in its 
dimensions and is called a spore. Thus, the process involved in spore 
formation does not differ from that of fission but occurs a greater num- 
ber of times within the enclosing capsule. In budding or gemmation a 
piece of the nucleus is pinched off from a certain part of the mother cell 
and becomes the nucleus of a new cell. If a vast number of buds are 
formed in this manner the result resembles that of spore formation. 
This is common among the Suctoria. Therefore it does not matter 
whether or not a cell divides by either of the above methods the process 
is essentially the same. From the fact that these modes of division are 
common among the earliest forms of animal life it may be inferred that 
they are the simplest modes of division, and yet there seems to be no 
adequate explanation of them because no visible changes are apparent 
in the chromatin in accordance with any recognized law. Cleavage does 
not indicate its cause by any visible act whatever and observation fails 
to detect the commencement of activity. 

Indieect Cell. Divisioit ok Kakyokinesis or Karyomitosis. 

This mode of division occurs in the majority of animal and plant cells 
especially of the higher orders. Much attention has been given to the 
relation of the centrosome to this form of division and the conclusion is 
that in those cases where it continues from cell to cell it may be con- 
sidered as the vehicle of some chemical substance which initiates mitosis 
or chromatin activity. But it is not always present and karyokinesis 



16 A COXSTRUCTIVE METHOD IX HISTOLOGY. 

does not seem to be affected by its absence. The present knowledge of 
this method of division is based upon the pictures produced by the chro- 
matin activity of the nnclens. Since chromatin stains readily it may be 
observed from time to time and although the chemical changes escape 
detection their results may be seen in the arrangements of the chromatin. 
Having once begun, a continuous, progressive series of changes takes 
place in the chromatin until cleavage occurs when the process terminates 
and a reversal of the new chromatin products to a resting condition is 
apparent. If four persons stand on the bank of a flowing stream, each 
one ^ve miles distant from his neighbor, and each one describes the 
scene before him, it is evident, that four different views would be pre- 
sented while the same stream would be moving on through them all. So 
with the observers of karyokinesis. Different views are obtained ac- 
cording to the time and place of observation and these views are called 
the stages of the process. They are, perhaps, infinite in number, but are 
usually considered and described under four stages, viz., prophases, 
metaphases, anaphases and telophases, which may be examined under 
the following outline and in plate 11. 

Cell Division. 

1. Simple Direct Division or Amitosis.—A primitive form of division 
common to the Protozoa. Probably binary fission occurs in the greatest 
number. Spore formation occurs in the sporozoa and budding or gem- 
mation in the suctoria. This form of cell division is not well under- 
stood. Apparently the centrosome does not divide and takes no part in 
the process. Chromosomes are not formed by a transverse breakage of 
chromatin loops. The nuclear substance undergoes a division of its 
whole mass without apparent cause. This form of division occurs fre- 
quently in pathological growths and appears to indicate a retrogressive 
act. It is rare, if it occurs at all, in normal, physiological growths. If 
spirogyra be placed in water containing 0.5 % to 1 % of ether it divides 
rapidly by amitosis. If the same individuals be placed again in water 
they divide by mitosis : so that the character of the irritant causing the 
division governs the particular form of division which will follow. 

Varieties: Biliary Fission,— The nucleus slowly elongates, becomes 
dumb-bell in shape, then constricted to a thread and finally into two equal 




Tieitlfif f"-'' 








k-.a'i-t V t'Tcf-^^^i- 




\\N1| 



$iiH Ltet^ iUn © 




C^ai'is^ '?\'&}'hdC. 




F 




l-ast ?roj>^^ie. 





JX^l.f/>*^^ C'e/^l. 



^u^?ife)' C«/^ 



PLATE II. 
Djagrams of Mitosis (after Wilson) 



17 



18 J. : r^ucnvE mbthob m msroLoer. 

jiarts eadi one of ndiidi bee- : :zir ? i^e new nodeos of Ihe new celL The 
division of 1^ eyto^asm HitL : : ^ows and the division is oomi^eted. 

Spore Formatiam^— The c^ is enidosed in a eystie cs^psnle and tiien 
fhe nnelens divides into a great nmnber of very small parts eadi one of 
idiidL is eaOed a spore. These spores, by growfli and development^ be- 
ccnne new eens. 

Bvddmg or - — ^ ir r :: Lr ::: .r :- is ::± i^l - :*rom 

a certain pm-t of iir i_ It: :r\'. ::: l^t^ Lr -:.:[rz.- :: iir Lt"^ rlL 

2- Imdirectl -Z _ Z i :: 

Progresswe Stages: Prophast: ?i r II z^'= .1, Z C I', E, F. 
Meta^uises, Plate H fig. H. ^;^ ? : : r H. z^-. L T: ' _ H3ses,, 

Plate IL figs, J, EL 

Pre — _ /loiu; Changes, — The ehromatin of the imdeos 

inereasr- .7 in s: lining {rawer, loses its net-like arrangement, ab- 

sorbs ::- n ilear n _ ane, resolves itself gradDallj into a convofaited 
thread or closed skein or spreme wbidi flien ihiftkffns and shortens to 
form an open skein or spireme or wreath idddi then divides transverselj 
into a definite nmnber of straight or curved rods called dKromosomes. 
flach species of plant or animal has a fixed and diazacteristie nnmber 
of diromosomes and in all forms of sexnal re|Ht)daciion fliat number is 
e"ez. In larks flie number is 36. In gasterojrads 32. In the inoi=e. 
lily. :: : i: mander 24. In some worms IS. Zi iie guinea pig, ox, 
onion, man 16. In &e grasshojqper 12. (PL XL ngs. B, C, D.) 

Prophases — Achromatic dumges. — The achrtmialin now becomes 
oontinDOTis witii Hie cytoplasm. A fibrous spindle-shaped body appears, 
at eiflier pole of idiidi is a star or aster formed of rays of astral fibers 
radiating from a central point throng^ the snrroanding cyfoj^asm. In 
the center of eadi aster is flie centrosome snrTonnded by a centrosplieie. 
The centrasome divides into two similar halves, an aster forms aroond, 
eadi half, a spindle stretdies between &em and a body called ifae ampld- 
aster is formed. The diroinosomes become attadied to flie spindle 
which paDs fliem aromid its equator. This entire stroctore is known as 
the mitoiic or karyokinetic figore. (PL H, figs. E, F.) 

Metaphases — Chroauitic dumges. — The chromatin net-work, whidi 
has been converted into a tangled Hiread and whidi is contiimoos in &e 
form of a thread or dtsconiinnoiis in &e form of cbromosoines, splits 



TEE CELL. 19 

throughout its entire length into two exactly equal halves. (PL II, 
fig. H.) This is the most important step in the process of cell division. 
Metaphases— Achromatic Changes.— HhQ spindle exerts some control 
over the arrangement of the chromosomes since they are, with great 
regularity, distributed around its equator and along its meridians by 
virtue of some sort of attraction or mechanical connection. (PL II, 

fig. H.) 

Anaphases— Chromatic Changes.— The chromosomes, in two equal 
groups, separate along the meridians of the spindle and become crowded 
together in two equal masses at the centers of the asters. (PL II, ^g. I.) 

Anaphases— Achromatic Changes.— A.^ these two groups of daughter 
chromosomes diverge they are connected by a bundle of achromatic 
fibers stretching across the interval between them known as Interzonal 
Fibers. These fibers are regarded as a central spindle within an outer 
mantle of spindle fibers to which the chromosomes are attached and 
which become visible as they separate. During this period a series of 
deeply stained thickenings appear in the equatorial plane of the central 
spindle called the cell plate. (PL II, fig. H.) 

Telophases— Chromatic Changes.— 'ErgIq. daughter nucleus receives 
one half of the spindle, one aster with its centrosome and an equal num- 
ber of chromosomes and hence the daughter nuclei are of equal size ; but 
if the division of the cytoplasm which follows is unequal the nuclei also 
gradually become unequal— a fact which shows that the size of a nucleus 
is governed by that of the cytoplasmic mass. (PL II, ^g. J.) 

Telophases— Achromatic Changes.— As a rule the spindle fibers dis- 
appear. A portion of them, however, sometimes remains. The aster 
may disappear together with the centrosome or the centrosome may 
persist outside the nucleus and divide into two at a very early period. 
Constriction and division of the cytoplasm follow and the process is 
completed. (PL II, figs. J, K.) 

Retrogressive Changes.— Following the longitudinal cleavage of the 
chromosomes and their separation along the meridians of the spindle, a 
reversal of those changes, which led up to the cleavage, follows until the 
daughter nuclei show their chromatin in the resting condition of the cell. 
(PL II, figs. L, M.) 




the/>»-occs5 Of 



^xtUit, hjfolUs^ «lv^l m«S«*U»* (AftsrV^r. ii«nf(irhy 



PLATE III. 
Fertilization and Tissue Genesis. 



20 



THE CELL. 



21 



TISSUE GENESIS. 



Gkrm 
Cells. 


Cell Changes. 


Formative Processes. 




Di vi sion of 






chromatin. 






Extrusion of 






polarglobules. 






Loss of one 




1. Ovum. 


half of the 




Plate V, -1 


original num- 




Fig. 12. 


ber of chro- 
m s ra e s. 
Formation of 
female p r o - 
nucleus. 










Division of the 






Union of male 


new cell and 






and female 


formation of 




■^ 


pronuclei. -{ 


the blasto--^ 






Plate III, 


derm. 






Figs. 1, 2, 3, 4. 


Plate ni, 
Figs. 5-11. 




Division of 
chromatin. 
Loss of one 




2. Sperma- 


half of the 




tozoon. , 
Plate V, ^ 


original num- 




ber of chro- 




Fig. 13. 


m s o m e s. 
Formation of 
male pronu- 






cleus. 







Divisions of 

THE 

Blastoderm. 



Ectoderm or 
Epiblast. 

Plate III, 
Fig. 12. 



Parts of the Body Derived from the 
Three Divisions. 



Epidermis and appendages. 

Secreting glands of the skin. 

Epithelium of the mouth, salivary glands and 

nasal tract. 
, Enamel of the teeth. 
^ Lens of the eye. Ketina. 
Epithelium of the labyrinth of the ear. 
Epithelium of male urethra except prostatic 

part. 
The entire nervous system. 



2. Mesoblast or 

Mesoderm. 

Plate III, 

Fig. 14. 



3. Hypoblast or 
Entoderm. 
Plate III, " 
Fig. 13. 



1. Mesothe- 
lium. 



2. Mesen- 
chyme. 



3. Mesamos- I 



bold. 



1 



Striped voluntary muscles. 
Striped involuntary muscles. 
Epithelium of serous membranes. 
Epithelium of genito-urinary sys- 
tem, except bladder and urethra. 

Connective tissues. 

Smooth muscle. 

Spleen, lymph nodes and epithe- 
lium of blood, lymph vessels and 
spaces. 

Red and white blood cells. 



Epithelium of the thymus and thyroid. 

Epithelium of Eustachian tube and tympanum. 

Epithelium of the alimentary canal (mouth ex- 
cepted) and all the glands which open into it. 
Liver and pancreas. 

Epithelium of the respiratory tract and all the 
glands which open into it. 

Epithelium of bladder and prostatic urethra. 



The animal body is a c ^ t : : r o rtm inTiity of iadividoal parts all 
of wMcli have a commnnity of intere - : - . The investigation ^diich leads 
one from a consideration of tiie whole to a consideration of &e nltimate 
parts reveals the organization by ^liiich that coTominnty of interests is 
maintained. The ch^nical elements of protoplasm, the ci^cimcal actions 
of these elements dnring metabolism, ttie chemical constitution of the 
waste matters of metabolism make it neo^sary that the same diemical 
elements be supplied to protoplasm in order that it may continne itself. 
The systems by which these dements are prepared, supplied and re- 
moved are the great systems of the body. The digestive system, be- 
comes a necessity because hydrations and solutions of substance con- 
taining tiie chemical elements of the body are essential; the respiratory 
system, because oxygen income and carbon dioxide outgo are essential ; 
the circulatory system, because a circulating liquid witii the ^emical 
elements in solution is essential ; the urinary system because tiie elimina- 
tion of waste matters is essential; tiie genital system, because the con- 
tinnation of the species is essential; the motor system, because change 
of location on the part of the animal and distribution of movable con- 
tents are essential; the systems of special sense, because the selection of 
food, protection of body and welfare of amrnal are ess^itial; tiie central 
nervons system, because a craitral administration of community affairs 
is essentiaL All of these systems have been gradually evolved along 
the line of animal progress according to the requirem^rts of animal 
mass. Systems, therefore, are collective assemblies whose united 
activities characterize tiie animal and express the jdienomena of animal 
life. The individual parts which constitute tiie systems and which are 
responsible for their concerted activities are called oigans. 

Tissues.— ThQ word ^ ^tissue" has been generally adopted and is 
understood to mean one of tiie four structural parts of ^diidi tiie body 
is composed. They are all composed of cdls and intercellular sub- 
stances and may be r^arded as tiie building materials of tiie body and 
its various organs. For the most j)art tiiere is differraooe enou^ be- 
tween them to render their identification possible. !Each tissue is found 
to occur in several forms known as varieties. The classification of the 



THE CELL. 23 

varieties is based upon the form which the cells and intercellular sub- 
stances have assumed and generally there are sufficient differences be- 
tween these varieties to enable one to recognize them. The four tissues, 
their varieties, descriptions, locations may be seen in the following out- 
lines and plates. 



24 



A COySTIiUCTITE METBOB IX HISTOLOGY. 



KPT TffKT.TAT. TISSUE. 



TaSLETIES, 



Descriptiox. 



Location. 



L SSraple. 



"L PavemenL sanamfMis. I! I --'-" "^ vessds, seroas membranes and j 

ti>s»4at«L^^^ One sinele laver rf oOls iji^ipiiadcs, air cells, msstoid cells, 

of brain. Poetenor sarfaoe of an- i 



dothdiom. 



Plate IV, Figa. 1, 5. 

- 2. Cubical, colnmnar, 
cvlindjicaL 
Hate rvr. Figs. 2, a 

3. COiaied. 

Hate IV, Fig. 4 



I united by^ eoanrait. 



tenor capsule of eryslaUine lensL 



J One sn^ lajer of odls J Alimraifaij canal columnar frmn eash 
) united by cement. | diae end of atmnaidi to anus. Ducis. 



J One sin^ layer of 
-^ united by eemeai. 



2. Saati&ed. 



L FaTement, scaly, | Sereiallayeis of odb united 
squamous, tessel-J by cement. Denser cells 



IL Paendo^tiati- 
fied. 



4. TnmsitionaL 



5. Pdygonai, poly- I 
hcdral, glan-'( 
dolar. 



lated. 

Hate IV, Fig. 6l 



2. Cfdnmnan 

Plate IV, Fig. 7. 



3L Ciliated. 

Plate IV, Kg. 8. 



1. Colnmnar. 

Plate V, Fig. 14. 

2. Oliated. 

Hate V, Fig. 14. 



are columnar and flatteni 
oat towaid the snrfacR. I 



I Utein^ half of cerrrs: uteri. Fallopian 
4 txtbe, Tentrides of brain except the 
I fifUi, central canal of spinal cord. 

;^ideimis, mouth, tcmgnc, -voial cords, 
epi^^ottis^ cesof^agus, cornea, ciSso- 
tory part of the nasai mneoea, exter- 
nal auditory canal, lover h*lf of 
eerrix uteri, Tagina, ^ans penis, 
anus, labia miccra, female urethra, 
meatus u r»"»"»ig of male nr^hisk 



^^"^St °I^r^ I P»U of T« e«^,^ eoni ™»>od 
round or p<4ygonal, be-^ 
eoming columnar irtien I 
leqniiid. 



of testicle, poidulons male orethra 
and upper part of lafdirrmal duet, 
ras deferens exo^ first part. 



Same edi arrangement 
described above in 
colnmnar type. 



as I 
the^ 



Lower part of ladtrymal duct, res- 
piratory part oil n^al mucosa. Eu- 
stachian tube, larynx, traidiea, 
brondii, epididymis, first part of vas 
deferens. 



J A 8in^ .^^L£5fKj"*^ J Veaieala; aemlnales. 
J nadeiin diSeiait pHanesL I ^^^^ 



Polygonal, pear- 
shaped odls. 
Plate IV, Fig. 9. 



^.SS^-^^^^J^jf^^i Osseous part of Eustadiian tube, tym- 
^^wj^nuekumdifer-^ p^^P^^ 

In the number of layers 
midvay between &e samr- 

|de and stratified. Lower J Pelris of Hdney, ureters^ bladder and 
edis are pear-^baped and | prostatic portion of uirain. 
doT^ail into concaTe 
ui^erodls. 



iOdls of no definite shape 
united by cement, aip- 



whidi vary firtHU ■ 
flioes of a columnar^ 
type to tiiose of a ^ 
scaly type. i 



units of ^andular structure. 



^'*^™^i- A *S^^? J ^^^ of secreting ^ands and tubular 
UMinbrane lining the aeini^ ^^j^^ „f sbmdn&^rfroctare. 
of seerecmg glands and ' 
the tubular units of glan- 
dular structure. 




EhiihiLiitm' 




m 



3, 



Cii6^icai 



Cclkmnar C«(«imnar 




^im^ie Lav^ment'-^MMdiarn 




















St^atljiad Columnar 







Qj>ithelium 

Sttatif 4€«( -foirnis 



foote. 



PLATE IV. 



The Different Varieties of Epithelpjm, 



25 



26 



A CONSTRUCTIVE METHOD IN HISTOLOGY. 



SPECIAL EPITHELIAL CELLS. 



Varieties. 



Description. 



1. Goblet cells. 

Plate V, Fig. 1. 

2. Enamel. 

Plate V, Fig. 2. 



3. Pigment cells. 

Plate V, Figs. 3, 4, 5. 



4. Cells of crystalline lens. 
Plate V, Fig. 6. 



5. Neuro-epithelium. 
Plate V, Figs. 7, 8, 9, 10, 11. 



6. Ovum. 

Plate V, Fig. 12. 



7. Spermatozoon. 

Plate V, Fig. 13. 



Location. 



'^Thf'coCnar'^typJwUh ^^^^^^^ On surfaces covered with columnar or 

and^ a^umiStion of mScu^^^^ ^i^i^^d columnar epitheUum. 

Four- to six-sided columns united by , r^„-„-„„ xr,^ .q^„+i„„ ^f +i.« *^^u „= 
cement and containing 98/. of inorgani^Covenn^^^^^^^^ the teeth as 



Polygonal or polyhedral cells containing 
black pigment in varying amounts. 



A single row of short polyhedral cells 



1. Posterior surface of the iris. 

2. Retina of the eye. 

3. Membranous labyrinth of the ear. 

4. Rete mucosum of the skin. 

5. Cortical substance of the hair. 

6. Olfactory part of the nose. 

7. Lamina supra choroidea. 



whixjh develop into elongated lens fibers . Crystalline lens. 
united by cement and form a more or^ '^^J "«"""« *«"■»• 
less perfect double convex lens. 



Cells of various shapes and sizes placed 
between external stimuli and nerve fibers 
and so constructed that the nerve ele- 
ments and epithelial elements are blended^ 
into one cell which becomes a receiver 
and transmitter of impulses. 



1. Rods and cones of the retina, 

Plate V, Figs. 7, 8. 

2. Hair cells of the organ of Corti. 

Plate V, Fig. 9. 

3. Olfactory cells of the nasal fossa, 

Plate V, Fig. 10. 

4. Gustatory cells of the taste buds. 

Plate V, Fig. 11. 



A round cell dilTering from other cells in 
the equal division of its chromatin as it 

producing a third which develops under 
usual laws into the complete animal. 



i 



A cell of the ciliated type with the same 
peculiarities as the ovum. 



■{ Testicle. 







S^eCia( EhLiheCiam- 



Mad- 






.Ta 1 1 




|// ^/><^»"**02<><>n- v£5«fl/?<«/. yisualcone 




OLjaCtOfjf ipfUs. 



Taste C«Us. 




Zhlihelium of Crt^staUine 



Vi^fntpt CiU.!, of vetiyia- 




Vi^ment C«.LU of 
Yete muco&um. 




Tigtnent Cell of 
Lamina iufiro-Qharotdia (.ALlgi Ce.U 





EnAm^l Ctlli. 



PLATE V. 




simile kSiudo- &Lrnf>Le 
%tyaiifL«.d, bitoldo- 
CoLumnar s.tvati-fteti. 
eUthtUutn- Columnar 
■ Ciliated 



Special Forms of Epithelium Occurring in the Generative and Sensory Systems. 



27 



28 



A CONSTRUCTIVE METHOD IN HISTOLOGY. 



COXNECTIVE TISSUE. 



Varieties. 



Structure. 



Description. 



LOCATIOX. 



1. Lymph. 



2. Specialized 
connective"" 
tissue cells. 



Cells. 
Plate VI, Fig. 5. 

Intercellular 
stance or plasma. 



I Small, colorless cells with large nuclei and small 
■{ amount of protoplasm called lymphocytes, 
I -which may be antecedent forms of leucocytes. 

1^ I An intercellular liquid with the same composi-" 
^ tion as blood plasma except that the proteid 
constituents are less in amount. 



Varieties. 



1. Pigment. 

Plate VI, Fig. 9. 



2. Osteoblasts. 

Plate VI, Fig. 14. 

3. Osteoclasts. 

Plate VI, Fig. 15. 

4. Myeloplaxes. 

Plate VI, Fig. 16. 

5. Erythroblasts, 

Plate VI, Fig. 17. 

6. Marrow cells. 

Plate VI, Fig. 18. 

7. Odontoblasts. 

Plate VI, Fig. 19. 

8. Phagocytes. 
Plate VI, Figs. 6, 7 

9. Neuroglia. 

Plax VI, Fig. 24. 



Description. 



Round or oval granules of black or brown color 
packed together within the cells. They may 
escape and show the Brownian movement. , 
Alone they are colorless. They may be excited "^ 
to aggregation or separation by nerve stimuli 
giving shades of any density. 



Lymph spaces and 
"vessels. 



1. Outer surface of 

choroid. 

2. In the iris. 

3. On the pia mater of 

the upper part of 
spinal cord. 

4. In retiform tissue of 

some lymph nodes. 

5. Sometimes in the 

spleen. 



Flat cells with large nuclei and many branches. J I' £l^!!w?f ^i?^°f: 



They are the bone-forming cells. 



J Large cells with many nuclei. They are the, 
I bone-absorbing cells. 



2. Beneath the perios- 
teum. 

In the irregular spaces 
of newly-made 
bone. 



-{ Large giant cells, not unlike the osteoclasts. ■{ Bone marrow. 

J Small red-tinted cells resembling nucleated red i t,„j v„„^ 

1 blood ceUs of the embryo. ^ Red bone marr 

J Cells like the leucocvtes except t>^„ they have j p^ti„ nmrrnw 
) larger, clearer protoplasm and larger nuclei. ' -^""^ marrow. 



I 

1 



I Pulp cavity of tooth on 
Long columnar cells with long and delicat«J the dentinal sur- 

processes. 1 face. 

Spherical, nucleated, amoeboid cells which de- i a„^„i,o«» 
stroy other cell life by their digestive abUity. "> -^^^y^iiere. 

Cells with many branches radiating from the , ci„^^^^i„„ «'>„.v,«™.«,v 
protoplasm. Ilthough from the ejSblast their^ "^^P^of ^fvfSr* 
tumors are called histioid. i v/ ^^ ^. 









SftLndU^ B?anchinf ptasmft PiaSTna LyTnj,KoC^t« 







ASorj<?I?ttC(€a?T^ay5§ttio)ial ?ott|ni«c(€ay Figment Ccl^ /slast Ce^^ 









Tat C«il . Tcndon. Cafi'd^^^ • OSt€o&ia sf Osteoclast M^^ I o |j Iav 













^^rtfthyoUaU Ma^-i'ow cc/i 




odontoblasts Red UoQd C^U 



3 I '^■0M^M 



Rud Uood C</( of 




Zd^d vt€ws J^QUfo^lia Cell 



PLATE VI. 

The Vaeiotjs Foems of Connective Tissue Cells Occubring in Blood, Connective Tissues 

AND Nebvous System. 



29 



30 



A COySTRUCTITE METHOD 7T HISTOLOGY. 



CONNECTITE TISSTl 



Taktettes. 



Stbttctukzs. 



1. WMte 

Fibrous. 

Plate vn. Fig. 

19. 



L Cells. 



2. Intercellular 
Substance or - 
Base. 



2 Yellow 

Elastic. 

Plate YH. Fig. 

a), 21. 



1. Cells. 



2. Intercellular 

Substance or 

Base. 



PESCBIPTIOy. 



1. Irregular. Plate TI. Fig. 2. 

2. Branching, Plate YI, Fig. 2. 

3. Spindie, Plate VI, Fig. L 

I; Leu(S?^es, i ^^^^^ ^ ^^S^ ^' 
6. Tendon, Plate VI, Fig. 12. 



Fine, "wavy, parallel, non-snasto- 
mosing fibers which swell up with 
acetic acid and yield gelatin on 
boiling. Cementl 



J Flat, irregular in shape, often 
I wrapped around the fibres. 



Large, anastomosing fibres which ! 
curl at the broken ends, do not ' 
swell up with acetic acid, do not j 
yield gelatin on boiling ; but do I 
yield elastin if high temperature ' 
is prolonged. Cement. 



OCCTJKS AS 



LOCATIOS^. 



L Tendons. •{ Attach muscles to bone, 

2. Ligaments. 4 Connect bones together 
° I fonning joints. 



3. Membranes. 



Periosteum, perichon- 
drium, dura mater, pia 
mater, serous mem- 
branes, sclerotic coat of 
eye. 



4- Aponeuroses ^ Expansions which unite 
or Fascia. \ muscles. 



1. Ligaments. ^ 

2. Membranes. -{ 

1 

3. Areolar I 
Tissue. I 

4. Yellow 
Elastic 

Cartilage. 



1. Ligtimentnm nnchae. 

2. Ligamentum subflara. 

Fenestrated membranes 
of blood-Tcssels. 

ETcrywhere. 

External ear. Eustachian 
tube, epiglottis and cor- 
nieula laryngis. 



CONNECTIVE TISSUE.— <7w«wtted. 



Varieties. 



STRrCTURE- 



Descripttox. 



LocATiojr. 



; 3. Areolar or 

cellalar. 
Plate VII, 
Fig. 15. 



A combination of white 
fibrous and yellow 
elastic tissues. Both 
varieties run in all-{ 
directions and present ; 
the same structure as \ 
the separate tissues. { 



4. Mucous, em- I L Cells 
bryonic or I 
gelatinous. '^ 
Plate vn. 
Fig. 16. 



2. Intercellular 
stance. 



Bub- 



5L Lym p h o i d 

or adenoid, 
retiform or! 
reti cula r. i 
Plate vn, 
Figs. 17, 18. 



1. CeBs. 



Intercellular 
stance. 



sub- 



A soft, fleecy, supporting or a firm, | 
dense uniting tissue of open or 
close texture according as free 
motion or firm connection of the , 
parts supported or united is re-^ 
quired. Wherever it is it is a tis- I 
sue of spaces which have given it 
its name. 

Round, branching or spindle ac- 
cording to the stage of advance- 
ment present. ] 

In round cell areas has no structure, \ 
in complete cell areas has the 
siructore of fibrous tissue. 

Leucocytes or white blood cells or 
lymph cells in the meshes of the 
retiform structure. 

Cells with deUcate, unitingbranches 

which enclose spaces and form the^ 
framework of the tissue which is 
called reticular or retiform tissue. 
A lymphoid tissue then is a -reti- 
form or reticular packed with 
leucocytes. 



Forms the subcutaneous tissue, the 
subserous and submucous coats 
of serous and mucous mem- 
branes, the sheaths of muscles, 
blood vessels and nerves and 
connects organs and parts of 
organs. If all the organs were 
removed it would form a model 
of them all. 



Found in umbilical cord of foetus 
as "Wharton's Jelly. Does not 
occur in the adult 



Found at all the entrances to the 
body ; beneath the mucous mem- 
brane of the pharynx, tonsils, 
tongue, oesophagus, stomach, in 
the solitary glands, Peyer's 
patches and villi of the small in- 
testine, in the solitary glands of 
the large intestine, in the mucosa 
of the appendix, beneath the 
mucosa of the larynx, trachea, 
bronchi and utenis and in 750 
lymph nodes. 




Adtf>ose tissue. 





HjfaLine Cav-ti/a^e. 




W/itt C f/'/vo Cavtlia^i 



SqUospq elaHic CayiiLge. 




A^'eoiar tissue. 




tissue 
J.0 





„ ,., jv y W/iitc ^i^vo^s tissue • 

"feissae. 




v^/zLvAi' Jli" ""i " \ ." " C»«oss ScciioM of yeUosAt dUstic t:i^$ue, 

leUoSN e/a&ttc tissue- 



PLATE VII. 
The Vaeieties of Connective Tissue. 



31 



A COSSTJmCSITM MVETHCSi IS HISTOLOGY. 



^ 1^ — '. _ n:-: a-t' 



TAHrSTEES. 



LCGTrK-E. 



LOCATTOS". 



^1. CeO^ 






|2. Intar^eniE^er , rjtan-nt- 

H ftlK&ltfiiBHPB' ' 






L Cdlls. 



L TmJjiHWfipnkTT^ if 



except ia t&e Tttnga, eyelids j 
sod. penes sa^ within tKe 



r CdHs wit& maBBT" xadxs^m^ ^rsBctes wfa&:& 

I port of Bfflrre- e^[I&. i 

J A nuadrfiffii fbrai of cotiiteeti^e Tassiie fibril- 
1 lar suhstasacs. 



^ABEBOmK. 



~T3.I7C"i'L it: 



IL Ca3k 



ina,FSg^iz. 



hi: ;a-a.^:e. 



3L Tti fan, ^fi^fr'fiw 



2. W Mteffl fegL 



3L YiillWiii tJlMW- ' 



^ i3cai?TX03r. 

J.Sount, o-il and en- 
1 capauiaxeiL 

I 

[ Without atmc tare"' 
-< aad. looks Like. 
[ grooad giaa& 






1' cnnd in 2.er^e jiasue as a sop- 
port. 



ITaksg np lie t&yTofil, cricoid 
and axytenoid cartilages of 
the laiyiLi^ aJae of aoae, riaga 
of the traciiea, plates of the 
broncM, unites the riba to 
the atemum and covers the 
joiiit soT&Kes of hooes. 



\ 



csrfelEages sf^ Ifte fc^ anA 
pE^es A tihe jnils ei* Ifte 
ahspeai piafie in tiie 



taxdona. 



geeovcs of 



-{. Same as the hyaline. 

{I A hyaline base awfiFtly J 
-I transformed to yei- 1 
I low elastic tiasue. 



MsAxs ap t^ SasradatRm of 
tube, 

cornicula 



tte 
SavfBgHh. 




T4riod;«um 



Rxtivnal CiYCutn{«\r<ihtial 



\Aa's/<iYsi<xr, iysUtn. 



InhrwalCitCtimfifehiiiai 
iafmHag. 

Lacunae. 



PLATE VIII. 
Cross Section of an Entire Bone Showing Microscopic Structures. 



33 



84 



A COySTRUCTIYE METHOD /.Y E18T0L0GY. 



CONNECTIVE TISSUE.— Cbft/mt/ed. 



Varieties. 



Divisions. 



DEsCRIPTIOX. 



Basis 



Struct CRE. 



Description. 



Chemistsy. 



1. Compact J 
or Dense. ^ 



9. Bone. 
Plate YTH. 



2. Cancel- 
lous or 
Spongy. 



Consists of Harersian sys- 
tems united by lamellae 
around which are sereral 
circumferential lamellae 
and in the center of all i8-{ 
the medullary canal con- 
taining marrow, blood- 
Tessels, lymphatics and 
neryes. 



Cancellous bone does not 
differ essentially from the 
compact It has more 
spaces in proportion to the 
bone structure than the 
compact. There is no 
abrupt line b e t w e e n* 
them. The spaces of the 
compact widen out and 
those of the cancellous 
narrow down as one Ta- 
riety changes into the 
other. 



HaTcrsian 

Systems. 



1. Lamellse, 
Plate VIII. 



2. Lacunae, 
Plate Vni. 



3. Canaliculi, 
Plate Vni. 



4. Haversian 

Canals. 
Plate Vin. 



Circular layers of true 
bone-products of the 
bone cells or osteoblasts 
surrounding Haversian 
canals or uniting Hav- 
ersian systems. 

Minute spaces between 
the lamellae containing 
the osteoblasts and ar- 
ranged around a com- 
mon center. 



Minute canals leading 
from one lacuna to an- 
other and to the Haver- 
sian canals and con- 
taining the processes of 
the osteoblasts. 

Canals in the center of 
Haversian systems for 
the passage' of blood 
Tessels. 



Sixty-seven per 
cent mineral 
matter and 
thirty-t h r e e 
per cent ani- 
mal matter 
which yields 
gelatin on 
boiling. Both 
are so blended 
that chemical 
action only 
can separate 
them. 







OdontolrLa$t$ 
VuLf- 



Cement urn- 



Aj>ical f ommcn- 



Tooth. 



PLATE IX. 



Longitudinal Section of a Tooth Showing Microscopic Structubes. 



35 



86 



A C02;STEUCTIVE METHOD IN HISTOLOGY. 



CONNECTIVE TISSUE.— Coniimced. 



Two Sets. 



Varieties. 



1. Tvrenty tern 
porary teetli. , 
Ten in eacii"^ 



Teeth. 
Plate IX. 



Two second 
molars Two 
first molars. 



3. Two canines. 



Two lateral 
incisors. 



1. Two central 
\ incisors. 



8. Two wisdom. 



7. Two second 
molars. 



Two first 
molars. 



5. Two second 
bicuspids. 



Structure. 



Description. 



1. Membrane ^pitl^^li^l remains of the enamel organ 

' of Nasmyth ^ covering the young enamel in the form 

■ I of a thin membrane. It is soon worn off. 



I Hexagonal columns extend- 
Prisms. -j ing from dentine to sur- 
I face. 



2. Enamel. 



3. Dentine. 



4. Dentinal 

tubules. 



Sheaths of 
Neumann 



Chemistry. 



I Oblique lines passing 
Lines ofj through the enamel^ 
Ketzius. I caused by periodic deposit 
1 of calcium salts. 



Lines of J 
Schrager. | 



Parallel lines caused by 
differences in refraction. 



98 5^ m i* e r a 1 
matter. 

2 ^animal mat- 
ter. 



J Parallel fibers united by mineral cement] 78 5^ m ineral 
I extending from pulp cavity to enamel. ] matter. 



A system of minute, communicating 
canals, curving like the letter S, origi- 
nating in the pulp cavity and ending in 
the interglobular spaces. They contain 
the prolongations of the odontoblasts, 
called dentinal fibers. 

'J Dense, mineral ground substance enclos- 
I ing the dentinal canals. 



Thirty -two 
permanent 
teeth. Six--: 
teen in each 
jaw. 



4. Two first 
bicuspids. 



3. Two canines. 



2. Two lateral 
incisors. 



G. Interglobu- 
lar spaces of ^ 
Czermak. 



7. Apical fora-^ 
men. 



Cementum 
or crusta^ 
petrosa. 



9. Pulp cavity. 



1. Two central 
incisors. 



Irregular, branching spaces in the dentine 
under the enamel where calcification 
has not occurred. When small and 
numerous they produce a granular ap- 
pearance called granular layer of Tomes. 

Aperture at the end of the fang through 
which blood-vessels and nerves enter 
and emerge from the pulp cavity. 

A bone structure, without Haversian 
canals, covering the fangs. It contains 
a great number of Sharpey's fibers un- 
calcified. Its lacunse communicate with 
dentinal tubules. 

A central cavity occupied by connective 
tissue fibrils, branched connective tis- 
sue cells, a semi-liquid ground sub- 
stance. At the surface is a layer of 
columnar cells — odontoblasts — which 
send two or more processes into the 
dentinal tubules and one into the pulp. 

[A fibrous tissue membrane which is the 
10. Peridental J periosteum of the alveolus, continuous 
membrane, j -Hrith the cementum and blends with 
I submucosa of gum. 

Blood-v«ssels enter by apical foramen, 
pass through pulp, divide into many 
branches which become fan-shaped, 
then extend into a capillary plexus 
which spreads out between the odonto- 
blasts and dentine. Lymphatics have 
not been demonstrated in the pulp. 

Some medullated nerves enter by the 
apical foramen, lose their sheaths, di- 
vide into fine fibers which form a plexus 
under the odontoblasts Other medul- 
lated fibers reach the outer part of the 
pulp, lose their sheaths and form a 
second plexus communicating with the 
first; fiom this small branches extend 
between the odontoblasts and into peri- 
dental membrane. 



11. 



Blood V e s- 
sels. Lym-- 
phatics. 



12. Nerves. 



TISSUES. 



87 



CONNECTIVE TJSSVK— Continued. 



Varieties. 



11. Marrow. 



Bone 
Formation. 



Varieties. 




Description. 


Location. 


1. Red. 

2. Yellow. ' 


A delicate, areolar tissue in which are found a few 
fat cells, many marrow cells or leucocytes, nu- 
cleated red blood cells and certain large cells with 
many nuclei called myeloplaxes. Cells are some- 
times found containing one or more red blood 
cells. The tissue is very vascular. Red marrow 
is one of the sources of the red blood cells. 

A delicate, areolar tissue as a supporting framework 
for blood vessels and nerves in which are found a 
great many fat cells and other small cells resem-' 
bling leucocytes. A fine, vascular, areolar tissue 
lines the medullary canal called endosteum. 


Found in the spongy ends 
of the long bones, in the 
cranial "diploe," in the 
bodies of the vertebra?, 
the sternum and the ribs. 

Found in the canals of the 
long bones. 


Varieties. 


Description of Formation. 


Location. 


1. Intramembra 

■ 

2. Intracartilagi 


nous. ■ 
nous. - 


1. Model of future bone in white fibrous tissue. 

2. Increased vascularity of the connective tissue. 

3. Connective tissue fibers become larger and less wavy. 

4. Become impregnated with granules of lime salts. 

5. Granules fill the fibers and form spiculae-osteo-genetic. 

6. Granules deposited between the fibers. 

7. Union of osteogenetic fibers forms a meshwork. 

8. Osteoblasts are arranged within the meshes. 

9. Production of true bone by the osteoblasts. 

10. Extension of bone from the center by the osteoblasts. 

11. Absorption of lime deposits by osteoclasts. 

12. Result— a flat bone. 

1. Model of the future bone in hyaline cartilage. 

2. Enlargement of cartilage cells and their arrangement in 

columns. 

3. Calcification of the cartilage base and in closure of car- 

tilage cells. 

4. Penetration of the sub-periosteal tissue by sprouts of 

protoplasm. Fibers of Sharpey. 

5. Formation of irregularly-shaped spaces by absorption. 

6. Covering of the surfaces of these spaces with osteoblasts. < 

7. Production of true bone tissue by the osteoblasts. 

8. Absorption of the central part by the osteoclasts. 

9. Formation of peripheral layers of bone in the same 

manner. 

10. The bone-forming cells — osteoblasts — and bone-absorb- 

ing cells— osteoclasts— increase the dimensions of the 
forming bone by their combined activities. 

11. Result — a long bone. 


Flat Bones. 
Long Bones. 



38 



A COySTRLCTITE METHOD IX HISTOLOGY. 



CONNECTIVE TISSUE.— Cfc/i/iHi/ed. 


Variety. 


Structure. 


Varieties. 


Divisions. 


Description. 


Varieties. 








1. Bird, fish or 
reptile. 
Plate VI, 
Figs. 21, 23. 


Biconvex, nucleated, ellip- 
tical disks varying in size. 
The Petromizontidae have 
the round ceU. 






1. Cells. 


1. Red. 


2. Mammal and 
man. 

Plate VI, -^ 
Figs. 20, 22. 


Biconcave, non-nucleated, 
circular disks from 1 2700 
to 1 12000 inch in diam- 
eter, composed of fatty 
pelicle or stroma within 
which is haemoglobin. 
Camel tribe has the ellip- 
tical cell, 5,000,000 per cm. 




12. Blood. - 




2. White or leu- 
cocytes. 

Plate VI, ' 
Figs. 5, 6, 7, 8. 

3. Blood plate- 
lets or third 
corpuscle or-= 
haematoblasts. 


Spherical, amoeboid, nu- 

1. Bird, fish or cleated bodies of varring 
reptile. 1 diameters, 1 5000-1 2-500 

inch. -i 

2. Mammal and J game as above, 
man. 1 

1 -Rjwj «=,!, /^« 1 Small, discoid, amoeboid 
?p^ii. -< ovai bodies without color, 
reptile. ) ^,^2500 inch. 

^■ma™""^^ ^^"^-l Same as above. 


Polynuclear neutrophiles, 70^. 

2. Small lymphocytes, 2(K. 

3. Large lymphocytes, 2-4^. 

4. Cells with an irregular-shaped 
nucleus, 2-41. 

5. Eosinophiles, l-4ft. 
Percentages vary. 


Structure. 


Structure. Description. 




1 

i -crsvx,,- ] A globulin of the plasma obtained by half saturat- 

1. Fibrinogen. ^ ing plasma with sodium chloride. 


1 
i 


2. Liquid inter- 
cellular sub- 
stance or 
plasma or ' 
liquor san- 


1. Fibrin. <i 


rru-nr^^v.;^ I Produced bv the combination of calcium salts,; 
-• J-firomDin. ^ prothrombin and a ferment. 

8 A Ume salt. ^ Some salt of lime is necessary to formation of 






1. Water. 


' 


guinis. 


2. Serum. 


2. Serum albumen and serum 
globulin. 

3. Inorganic salts. 








S/jowtn^ SarcoitjfUs. 







Heart tnu^cd 





Cross Seciion oi o Sti-tU*^ 
4i 



Ci'oss Section of Sjnooth m^sc/c Cells. 



Smocih hiuscle Cell. 




PLATE X. 



Vakieties of Muscle. 



39 



40 



A CONSTJWCTITE METHOD IN EISTOLOGT. 



MUSCULAR TISSUE. 



Vakik.ties. 



1. striped Vol- 
untary. 



Divisions. 



Structure. 



1. Fascicul i , 
Lacerti or 
Bundles. 
Plate X, 
Fig. 1. 



1. Epimysium. 



2. Perimysium. 



3. Endomvsium. 



4. Fibers. 



Descriptiox. 



2. Fibers. 

Plate X, 
Figs. 2, 3, 4, 5, 

6 and 1. 



1. Sarcolemma. 

2. Sarcostyles 
muscle columns 

3. Sarcoplasm. 



4. Sarcomeres. 



5. Sarcous elements 



1 Ck)nnective tissue sheath around outside of a 
1 number of fasciculi. Plate X, Fig. 1. 

J Connective tissue sheath around each fasci- 
1 cuius. Plate X, Fig. 1. 

I Connective tissue extensions from the peri- 
-| mysium between the muscle fibers. Plate 
I X, Fig. 1. 

Cylindrical bodies with round edges and al- 
ternating light and dark stripes trans- 
versely arranged. Plate X, Fig. 1. 

J Structureless membrane around each fiber. 
1 Plate X, Fig. 3. 

o r J Divisions of the fiber longitudinally. Plate 
s. 1 X, Fig. 4. 



■{ Cement uniting the sarcostyles. 



6. Dobie's 
Krause 
brane. 



Line, 
mem 



Parts of the sarcostyles between any two 
membranes of Krause. Plate X, Fig. 5. 

Parts of sarcomeres I Two series of tubes, 
between any two J each series extending 
light stripes. | from Hensen's Disk 

Plate X, Fig. 6. I to light stripe. 



7. Hensen's Disk. 



8. Nuclei. 



9. Areas 
heim. 



of Cohn- 



Line or membrane in the middle of the light 
stripe. Plate X, Fig. 4. 

J Line in the middle of the dark stripe. Plate 
i X, Fig. 6. 

I Oblong bodies with little or no protoplasm on 
J the under surface of sarcolemma in mam- 
I mals. In the fiber in frogs. Long series in 
1 the middle in insects. 

Small polygonal areas separated by fine lines. 
They are the cross sections of the sar- 
costyles. 



Desceiptiox. 



2. Striped In- 
voluntarv. . 

Plate X, "I 
Figs. 7, 22. I 

3. Unstriped In- | 
voluntary. 

Plate X, 
Figs. 8, 9, 10. 



Short, anastomosing fibers faintly striped transversely, without sarcolemma, with 
prominent nuclei and longitudinal striations. Sections should be cut parallel with - 
the surface in order to make the stripes visible. 



Location. 



Skeletal. 



Heart. 



I The walls of 
Long, slender, spindle-shaped cells held together by cement. A long, blunt nucleus ^^le bol- 
ls situated in the center. The protoplasm is longitudinally striped, the striations-=^ j^^ ^is- 1 
being continued into the nucleus. cera. I 



wA 




frotn ij>inal Cord 



Ner\/e Cells, jO-res. Neui-onc 



|ferv€ t<rm « notion- 

/Ycttpont 
PLATE XI. 
Vaeious Types of Nerve Cells and Fibers. Neuron. Neuroglia, 



41 



42 



A CO^-STRUCTIVE METHOD IX HISTOLOGY. 



XERVOUS TISSUE. 



Divisions. 



1, Gray 
matter 
or cells. 



Varieties. 



Description. 



Cells of the!^^'^5'l^°?^'l,^^^^°fi°'?- 
^ *^ I nerve fibers. 



Varieties. 



1. SphericaL 



2. Ellipsoidal. 



Description. 



Location. 



2. Cells of the 
second type. 



Axis cylinders do not leave 
the gray matter, but after 
dividing and subdividing 
envelope the other nerve 
cells in their vicinity. 



3. Pvriform. 

•{ Plate XI, Fig. 9. 

4. Pvramidal. 
Plate XI, Fig. 7. 

5. Stellate, 
Plate XI, Fig. 8. 

6. Neuroglia, 
Plate XI, Fig. 5. 



Large, round cells with nu- 
cleus and nucleolus. Uni-J Ganglia, 
polar. I 

J Large, elongated cells with I 
A nucleus and nucleolus, k Spinal cord. 
I Bipolar. | 

Large, pear-shaped cells 1 
vrith nucleus and nucleo-^ Cerebellum, 
lus. Multipolar. I 

; Large, triangular cells with J p, , 
i nucleus and nucleolus. 1 »-«reDrani. 



i 



j Large cells with nucleus and I 

nucleolus and several-> Spinal cord. 

branches. | 

Cells with many branches i ^ ^ ^ ° 7 
uniting to form a frame-<! ^^'^^ ^^s- 
,x-^,v " sue as a 



work. 



support. 



Divisions. 



Structure. 



Description. 



Peculiarities. 



Areolar tissue surrounding 
a number of funiculL 



Epineuiium. -j 



Perineurium.4^-^«l^^-*^^? surrounding 



1. Funiculi.^ 3. Endoneur- 
inm. 

4. Fibers. 
Plate XI, 
Fig. 1. 



each funiculus. 



•J Extensions of perineurium 
1 between nerve fibers. 

I Prolongations of nerve cells 
-^ conveying impulses to and 
I from nerve centers. 



1. MeduUated. 
Plate XI, ■! 
Fig. 2. 



2. White 

matter ■{ 
or fibers, 



I A thin, structureless, nu- 
I cleated membrane inclos- 
1. Neurilemma. A ing the nerve. Absent in'' 
the white matter of the 
I brain and spinal cord. 



2. Fibers. ^ 



2. White sub- 
stance of- 
Schwann. 



3. Axis cylin- 
der. 



4. Axolemma. 



A framework of neurokera- 
tin in the meshes of which ^ 
is an oily matter called 
myelin. 

Central, conducting part- 
extension of the cyto- 
plasm of the nerve cell. 
I Divisible into fibrillae. 

J Delicate membrane s u r- 
"1 rounding axis cylinder. 



Constricted at in- 
tervals called^ 
nodes of Ran- : 
Tier. 

Absent at both 
ends of nerve 
and at regular 
intervals, nodes. 



An unusual pseu- 
dopodial exten- 
sion of cell pro- 
toplasm. 



White mat- 
ter of the 
brain and 
spinal cord 
and most 
ofthecere- 
bro-spin^ 
nerves. 



2. Non-medul- 
lated. 
Plate XI, 
Fig. 3. 



1. Funiculi. ■{ Same as above. 

Neurilemma. •! Not known to exist. 



-i 



2. Fibers. 



Axis cylin- 
ders. 



. A modification of 

J the same sheath 

I above described. 

Fibrillar plan more marked j 1 

than in the medullated. ] The number of j 
The nuclei are embedded-<; nuclei embedded 
in the outer part of the j in the outer part. | 
cylinder. | 



Chiefly in 
the s y m- 
p a t h et i c 
system. 




^ 3 




connective iii%ue 

Aeu)po-ehiiheliuTn. 
Tt^ciiU cti%k. 






^(XctiUCelU. 



yaciiU fndYxisCuS. 






-«_ — -^ -— jTuntCd^vo^vta. 







£n<i bulir of KfaUSf. 




XeUYO-^ithnUum. 
axis C(fLiY^c(.i\r. 

End J, tote 




Con<r«hfr«c 
Conn«ctiv« -tiiiut 
sheaths with 
rov/s j.^ *\ucl*c. 



MA<iuUci±tt( h«>>v«. 



Sl>(>a^ f(Alrc& wtt/) 
w/htch av« avts 



_//«vv« 



Tactt(c Coir/»t»sc(« of skin. 




Ganitaf Cot}fU%cU 






lipiil 
bi)]IJiii;i 



Connpctiv* tissue 
Ca/;&a(« Co«r»/>a$^f/»f 

ayis CytinJeYi. 
S«n)( fluid iuiitanc*. 



A<iyv€. 



End Ce a Of Core. 



attS C<^(tn€(«r 



End f)(att of mte«cl«. 




A«)rve 



Cofj^uicU of W«y^$t. 
irt?irv« t«irn»«nations. 

PLATE XII. 

The Various Forms of Nerve Terminations, 



43 



44 



A CONSTRUCTIVE METHOD IX HISTOLOGY, 



NERVE TERMIXATIO^TS 



Plax. 



Organs. 



Varieties. 



Description. 



Location. 



1. Tactile 
cells. 



. Simple. 
Plate XII, 
Fig. 3. 



1. Cells 
Merkel. 



of 

2. Cells of 
Eanvier. , 



A simple expansion of axis cylinder ' 
applied to the surfaces of epithelial , Epidermis 
cells or terminating within pear-' mammals. 
shaped epithelial cells. i 



2. Compound. 

Plate XII, 

Fig. L 



1. Corpuscles ' 

of Grandry. J Two or more epithelial cells with the [ Epidermis 
"1 axis cylinder expansion arranged be-^ birds and 

2. Corpuscles t ween' them. | mammals, 
of Merkel. 



of 



of; 

of 



The general 
plan seems 
to be to 
provide 
I the great- 
I est area of 
axis cvlin--{ 
der expan- I 
sion by ■ 
the most 
econ o m i c 
method. 



1. Genital corpuscles. 
Plate XII, fig. 6. 



2. Tactile 2. Articular corpuscles, 
corpuscles.^ 



3. Corpuscles of Meissner. 
Plate Xn, Fig. 4. 



1. Spherical and cylindrical. 
Plate XII, Fig. 5. 



End 
bulbs. 



4. End or- 
gans. 



2. Corpuscles of Herbst. 
Plate xn, Fig. 8. 

8. Key-Retzius corpuscles. 



4. Pacinian corpuscles 
Plate XII, Fig. 2. 



1. Organ of Golgi. 



2. Plexus of Meissner. 



3- Plexus of Auerbach. 



A conneetiye tissue capsule inclosing a 
core of polygonal cells a ' ' ' 

axis cylinders terminate 



core of polygonal cells among which^j ^^^ *° ^ ^~ 

Oval, connective tissue capsules with I 
large granular cores having many J Synovial mem- 
nuclei and one to four axis cylinders ] branes. 
terminating within them. j 

Connective tissue prolonged from a cap- I 
sule spirally in membranous septaj Skin of hands 
between which axis cylinders are I and feet, 
expanded. 1 

Elongated corpuscles into the center of j Conjunctiva 
which axis cylinders pass to end in an-\ and mucous 
expanded extremity. | membranes. 

A connective tissue capsule with a cen- | Skin and mu- 
tral core nucleated on both sides into^ cous mem- 
which axis cylinders pass. ] branes of birds. 

Intermediate between the Herbst and J Skin of tbebills 
Pacinian corpuscles. ) of birds. 



Twenty-five to fifty concentric connec- 
tive tissue lamellae lined by endothe- 
lium between which is serum. An axis'' 
cylinder passes through the center 
and terminates in a bulb. 



Mesentery and 
skin. 



Long, spindle bodies of tendinous bun- | Muscle attach- 
dles fused into one into which one or-s ment to ten- 
more axis cylinders pass. I dons. 

A gangliated plexus sending off fibers I g u bmucous 
to the epithelium of mucous mem--^' coats 
branes. coais. 



A gangliated plexus sending off fibers^ 
to smooth muscle. 



4. End plate of 
muscle. 

Plate XII, Fig. 



voluntary I Granular matter containing many nu- i 

A clei and nucleoli in which axis cylin--! 

I ders are embedded. I 



Between longi- 
tudinal and 
circular mus- 
cle of alimen- 
tary canal. 

Voluntary 
muscle. 



SECTION 2 

CONSTRUCTIVE METHOD BASED UPON THE TUBE PLAN 
OF STRUCTURE OF THE ANIMAL BODY 



THE TUBE AS A STRUCTURAL AND FUNCTIONAL 

UNIT. 

From simple observation of the animal body and its various organs 
in their natural positions it is evident that the tube forms a considerable 
part of them all. Reference to systems and organs, in italics, in the 
outline on pages 4 and 5, shows that most of them are tubes. Gross 
anatomy deals with visible structures such as the alimentary canal, body 
cavities, trachea, large and small bronchi, arteries, veins and lymphatics, 
ureters and bladder, uterus. Fallopian tubes, vagina, urethra, vas 
deferens, etc., and all are tubes of varying diameters and lengths. 
Minute anatomy deals with invisible structures such as the acini of 
secreting glands, alveoli of the lungs, tubes of the kidney and testicles, 
blood and lymph capillaries, etc., and these are very small tubes of 
microscopic sizes. Consequently whatever observation one makes, 
gross or microscopic, he is always dealing with tubes, large or small. 
The tube then is common to the greatest number of organs and is there- 
fore a necessary part of them as a unit of structure. The development 
of the vertebrate kingdom from primitive forms of life also directs atten- 
tion to this fact. The small dimensions of the Protozoa enable them to 
continue themselves and exhibit their phenomena of life without the 
presence of a central cavity; but, as physiological division of labor ad- 
vanced in accordance with an increase of animal mass, a time came when 
a central cavity was necessary for the nutrition of the animal and from 
that time the tube became the basis of animal structure. It was fore- 
shadowed as far back as Euglena viridis, a single-celled organism in 
which there was a slight indentation in the anterior end of the creature 
and which was set aside as a food tube of entrance to the small body. 
This simple tube in the low forms of life, developing into a complex sys- 
tem in the higher and highest forms, indicates the line of ascent along 
which animal progress has made its way. The worm, tunicate, fish, 
amphibian, reptile, bird and mammal— chief divisions of the animal 
kingdom— all present the tube as a common, fundamental structure of 

47 



48 A CONSTRUCTIVE METHOD IN HISTOLOGY, 

the body and of most of its viscera. Embryological development also 
reveals the tube in all its phases. After fertilization has occurred and 
the blastoderm has been formed' the whole period of prenatal life is con- 
cerned with tube formations and adjustments and when the creature is 
bom it is born as a large tube within which are arranged, in the form of 
viscera, a vast number of small tubes of all magnitudes— the kind of tube 
produced depending upon the functional requirements of the animal. 

A definite structure as universally present in body formations as the 
tube must have a functional capacity equal in variety and importance 
to the structural ; for the phenomena of animal life are the complex, con- 
stant results of chemical action taking place in the fundamental struc- 
tures of the body. In as much as the basic tube presents such a variety 
of forms, it follows that it will also present a variety of functions pro- 
portionate to the character of the structural changes. We find, there- 
fore, that tubes exhibit such functions as digestion, respiration, absorp- 
tion, circulation, secretion, excretion, reproduction, progressive and in- 
termittent motion of contents— all of which depend upon their structural 
variations. Since the animal first started as a simple, single tube it has 
not changed except in the number of tubes and the complexity of their 
arrangement. Metabolism, growth, motion and reproduction have 
always been the essential attributes of life, and they have been possible 
only on account of the tube activities of the body. The tube supply is 
the natural outcome of cell demand. For example, nutrition is absolutely 
essential to cell continuation and therefore must be provided for. Foods, 
by which it is maintained, are, as a rule, not adapted to cell metabolism 
until they have been subjected to certain chemical processes. These 
processes are made possible by the concerted actions of many tubular 
systems such as the respiratory, digestive, absorptive, circulatory and 
excretory. Whenever or wherever liquids, gases or solids are to be pro- 
duced and directed to some definite point the tube is a self-evident 
structure. 

Plan of Tube Arrangement.— The body is a large tube containing a 
prodigious number of small tubes which vary in diameters and lengths 
according to their functions. Some tubes are microscopic, others macro- 
scopic ; but the plan of their arrangement is the same everywhere. The 
microscopic tubes are joined by connective tissue to form the principal 



TEE TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT. 49 

viscera while the macroscopic tubes form the avenues of income and 
outgo for these viscera. Simple dissection determines that most of the 
great systems of the body conform to this plan, as for example— the 
respiratory, digestive, urinary, genital and vascular. The respiratory 
system is composed of enormous aggregations of alveoli or small tubes 
joined by connective tissue to form the lobules and lobes of the Imigs and 
of the small, medium and large bronchi, trachea and larynx which are 
large tubes of outgo and income for the gaseous products of metabolism 
and chemical elements of nutrition. The digestive system is composed 
of vast numbers of small, tubular secreting glands united by connective 
(issue to form the functional part, while the alimentary canal as a whole 
is a large tube providing for the income of foods, their digestion and 
absorption, and the outgo of waste. The urinary system is composed of 
myriads of small tubes united by connective tissue to form the kidneys, 
and of the pelvis, ureters, bladder and urethra which are large outgoing 
avenues of escape for the urinary products. The genital system is com- 
posed of a large number of small tubes which united by connective tissue, 
form the testicles or ovaries and of the vasa efferentia, epididymis, vas 
deferens, seminal vesicles, and ejaculatory ducts or Fallopian tubes, 
uterus and vagina which are the large tubes of exit from those organs. 
The vascular system is composed of tubes of various dimensions which 
form a complete circuit in the body — the small capillaries being the seat 
of nutritive processes, the large arteries and veins forming the avenues 
of income and outgo which render those processes possible. The secre- 
tory system is composed of enormous collections of small tubes— the 
acini— united by connective tissue to form the glands and of the outgoing 
ducts which are large tubes of escape for the various secretions. Thus 
the viscera are all formed according to the same plan of arrangement and 
economy of space, protection of delicate parts, certainty of action and 
successful operation are secured by this arrangement. 

Formation of Tubes.— While analysis makes us familiar with parts 
of which tubes are composed, if the process of investigation terminates 
with the separation and identification of those parts, we have a knowledge 
which is useful but imperfect. Synthesis of the parts is essential to com- 
plete that knowledge and afford us a proper conception of the whole 
structure which can not be obtained by mere application of the analytical 



50 A CONSTRUCTIVE METHOD IN HISTOLOGY. 

metliod. If we have discovered that all organs are composed of tissues 
and have not attempted to construct those organs by means of those 
tissues, we simply have discovered a collection of materials which are 
without purpose or significance. There are four tissues in the body; 
epithelial, muscular, connective and nervous, and each tissue is divided 
into several varieties. The varieties are the '* building materials" and 
present fixed peculiarities which give to them important values both in 
chemical and mechanical constructions. They are combined in many 
ways according always to design, and tubes are constructed the walls of 
which are usually described as composed of coats. The coats are com- 
posed of layers and the layers of tissues. A coat or layer is known or 
determined by its predominating tissue, although, strictly speaMng, 
almost any coat may contain all four tissues. Thus, by a connective 
tissue coat is understood a coat in which connective tissue can be seen as 
the charaxiteristic tissue. Muscular coats may have several layers and 
different varieties of muscle but muscular tissue is the predominating 
tissue. Epithelial coats may have several varieties of epithelial cells, 
may include a connective tissue base and possess some kind of muscle, 
but epithelium gives to it its importance and hence characterizes it. In 
the formation of tubes from tissues we may begin with the simplest form 
which occurs in the body, viz : the one layer tube, an example of which is 
the capillary and by a process of tissue addition arrive structurally and 
functionally at the most complex variety which may be seen in the four 
coated tube, an example of which is the alimentary canal. The one layer 
tube is composed of one, single layer of pavement epithelial cells united 
by cement and is the simplest cell structure in the body ; while the f our 
coated tube has nearly all the tissues and many of their varieties. Be- 
tween these two extremes of structure occur other tubes of varying thick- 
nesses depending upon the tissues present. For convenience they are 
named according to their structural composition as: one layer, one 
coated, two coated, three coated and four coated tubes. See Plate Xlla. 
Having some knowledge of tissues— their structure and purpose— it is 
only necessary to employ them as building units in order to construct 
any class of tube which may be desired. A one layer tube is always 
composed of one layer of cells and tissue additions are made according to 
the demands in each case and in no instance is anything more added than 



THE TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT, 



51 



is needed to adapt tlie tube to the office which it has to perform. In as 
much as there are many varieties of tissues, perhaps twenty or more, all 
of which seem to have different purposes, it is evident that a constructed 



fwXP^^^o^ A 




PLATE XII a. 

DiAGBAM Showing the Consteuction of the Five Classes of Tubes by Tissue Additions. 
Taking as a foundation the one layer tube, which is purely an epithelial tube, and adding 
to the outside a basement membrane, then a connective tissue base, then a muscular coat, 
then a muscularis mucosae, and all the tube classes with their component tubes may be 
constructed. 

tube will exhibit many functions. The tissues and their varieties are 
represented in the following seven plates. They are in the form of 
layers and coats which are curved. Visceral tissues are for the most part 



52 A CONSTRUCTIVE METHOD IN HISTOLOGY. 

arranged in circular form on account of tlie tubular character of their 
structural units. Most all of the epithelial, muscular, connective and 
nervous tissues of viscera are therefore situated on curved surfaces or 
enter into the formation of the walls of cylindrical tubes. We must 
think, therefore, of the tissues as always extending in directions equally 
distant from a central point. Tissues in layers and coats are numbered 
and described in the table which follows the plates. The colors represent 
the hsematoxylin and eosin stains and the numbers are the same as those 
which appear at the left of the case models. Coats of tubes are known 
by the following names: connective tissue, muscular, sub-epithelial or 
sub-mucous and epithelial or mucous. Plates XIII-XX which follow 
show the various varieties of the tissues in the form of coats and layers 
drawn on the same curve and numbered for constructive uses : 




PLATE XIIT. 

Connective Tissues as Outside Coats, Sub-epithelial Coats with oe without Secreting 

GlandSj Peyee's Patches, Solitary Glands and Bases of Epithelial 

Coats for the Construction of Tubular Organs. 



53 




PLATE XIV. 

Transvebse, Longitudinal and Oblique Layees of Striped and Smooth Muscle, Thick and 
Thin, fob the Consteuction of the Musculae Coats of Tubulab Obgans. 



54 




PLATE XV. 
Epithelial Steuctuees foe the Consteuction of the Epithelial oe Mucous Membeanes 

OF TUBULAE OeGANS. 



55 




PLATE XVI. 

EpITHELI.VL STErCTTTBES FOB THE Co:CSTBUCTIO>' OF THE EpITHELIAI. COATS OF MUCOUS 

3.IEMBEAXES. 



53 




PLATE XVII. 

Epithelial Stkuctukes for the Consteuction of the Epithelial Coats or Mucous 

Membranes of Tubular Organs. 



57 




PLATE XVin. 

CoNHECTivE Tissue, Epithelial ai^d Neubo-epitheliai. Steucttjres fob the CoNSixucTioiy 

OF Cebtain Coats of Tubtjt.ar Organs. 



58 




PLATE XIX. 

Connective Tissue and Neueo-epithelial Stexictubes foe the Consteuction of Cebtain 

Specim. Oegans, 



59 



60 A COySTRUCTIVE METHOD IX HISTOLOGY. 



MODELS ^TiIBEEED AXD DESCEIBED. 

1. Connective tissue. 

2. Connectiye tissue enclosing sweat glands, tactile corpuscles, blood vessels, nerves and lymphatics. 

3. Layer of striped voluntary muscle in transverse section. 

4. Layer of striped voluntary muscle in longitudinal section. 

5. Layer of smooth muscle in transverse section. 

6. Thick layer of smooth muscle in longitudinal section. 

7. Yery thin layer of smooth muscle in transverse section. 

8. Layer of smooth muscle in longitudinal section. 

9. Layer of smooth muscle in transverse section, 

10. Vascular layer of smooth muscle in longitudinal section. 

11. Layer of smooth muscle in longitudinal section. 

12. Layer of smooth muscle in longiradinal section. 

13. Layer of smooth muscle in oblique section. 

14. Layer of connective tissue with blood vessels, nerves and lymphatics. 

15. Layer of connective tissue -with secreting glands, blood vessels, nerves and lymphatics. 

16. Layer of connective tissue "with glands of Brunner, blood vessels, nerves and lymphatics. 

17. Layer of connective tissue with Peyer's patches, blood vessels, nerves and lymphatics. 

18. Layer of connective tissue with solitary glands, blood vessels, nerves and lymphatics. 

19. Basement membrane. 

20. Layer of connective tissue with blood yessels, nerves and lymphatics. 

21. Homogeneous layer. 

22. Layer of granular epithelial cells. 

23. Layer of stratified pavement epithelium. 

24. Layer of compound tubular glands with short necks, long bodies, chief and parietal cells. 

25. Layer of compound tubular glands with long necks, short bodies and chief cells. 

26. Layer of crypts of Lieberkuhn and villi resting upon a connective tissue base. 

27. Layer of incomplete crypts embedded in lymphoid tissue. 

28. Layer of crypts of Lieberkuhn resting upon a connective tissue base. 

29. Layer of erectile tissue. 

30. Layer of simple cubical epithelium. 

31. Layers of stratified, transitional epithelium. 

32. Layer of simple, ciliated epithelium in tubular glands resting upon a connective tissue cellular base. 

33. Layer of simple, ciliated epithelium in folds resting upon a connective tissue base. 

34. Layer of simple, cubical epithelium. 

35. Layer of elastic tissue, connective tissue and endothelium. 

36. Layer of stratified, ciliated epithelium. 

37. Layer of stratified pavement epithelium with undulating lower border. 

3-3. Layer of two rows of pavement epithelium — outer mostly non-nucleated— inner nucleated. 

39. Layer of simple columnar epithelium. 

40. Layer of endothelium (not in section). 

41. Layer of sustentacular cells, sperm cells and spermatozoa. 

42. Germ cell enclosed in embryonic epithelial cells. 

43. Layer of stratified pavement epithelium with border cells of columnar type. 

44. Layer of stratified pavement epithelium, 

45. Layer of simple cubical epithelium, 

46. Layer of stratified pavement epithelium, mostly without nucleL 

47. Layer of stratified, ciliated epithelium with long cilia, 

48. Layer of stratified columnar epithelium. 

49. Layer of rodded epithelium. 

50. Layer of polygonal epithelium. 

51. Layer of a modified form of connective tissue. 

52. Layer of connective tissue enclosing c-shaT)ed rings of hyaline cartilage and secreting glands. 

53. Layer of connective tissue enclosing plates of hyaline cartilage and secreting glands. 

54. Layer of nerve fibers. 

55. Layer of nerve cells. 

56. Inner molecular layer. 

57. Inner nuclear layer. 

58. Outer molecular layer. 

59. Outer nuclear laver. 



THE TUBE AS A STRUCTURAL AWD FUNCTIONAL UNIT. 61 



MODELS NUMBERED AND DESCRIBED.— Cowfmwefi. 

GO. Layer of rods and cones. 

61. Layer of pigment cells. 

62. Layer of simple pseudo-stratified ciliated epithelium. 

63. Layer of hair cells and sustentacular cells. 

64. Layer of hair cells, pillar cells and sustentacular cells. 

65. Layer of olfactory cells and sustentacular cells. 

66. Layer of simple pseudo-stratified columnar epithelium. 

67. Layer of simple ciliated epithelium. 

68. Layer of simple cubical epithelium. 

69. Layer of stratified columnar epithelium. 

70. Layer of connective tissue. 

71. Layer of connective tissue with pigment cells and many blood vessels. 

72. Layer of nerve fibers, nerve cells, ganglion cells, rods and cones and pigment cells. 

73. Thin layer of connective tissue. ■ 

75. Layer of simple cubical epithelium. 

76. Thin layer of smooth muscle in outer cross and inner longitudinal sections. 

77. Layers of connective tissue and endothelium. 

78. Layer of connective tissue upon which are blood capillaries embedded in the under surfaces of respiratory 

epithelium. 



Some confusion may arise in the usual distinction between a coat and 
a layer. As a matter of fact exact lines of distinction between the two 
are not drawn. A coat may be a layer or a layer may be a coat. In gen- 
eral a coat is composed of layers and hence is thicker than a layer. How- 
ever, both terms are merely convenient terms to call attention to a general 
fact concerning tissue thicknesses or masses and not to a fixed number 
of cells or fibers or a definite thickness or a mass of tissue, which is 
always capable of measurement. 

Arrangement of Tubes in Five Classes.— The different tubes vary in 
structure to a considerable extent; but if we examine them all and 
classify them on the basis of structural agreement we will find that nearly 
all of them, however widely apart they may appear to be, can be arranged 
under five classes which will be found to differ from each other by the 
presence or absence of some distinguishing part. The same functional 
requirements call for the same type of tube formation, so that if we know 
where a tube is and what it does we can build the type of tube which 
belongs to that location. A general tissue formula of construction is 
employed in order that tube types and not tube specialties may be made. 

The ^ve classes of tubes, constructed on a general formula, and 
examples of them beginning with one layer and increasing to four coats 
may be arranged as follows : 



62 



A CO^^STRUCTIVE METHOD IN HISTOLOGY. 



Type of Tube. 


FOBMATION OF TUBE. 


Example. 


1. One-layer tube. 


Epithelium or endothelium. 


Capillary. 


2 One-onated tubp -J 1 J Epithelium. ^ j Acini of any secreting 
z. une-coatea tuoe. 11 Structureless basement membrane. ] gland. 


3. Two-coated tube. 


2 J Epithelium. 

1 Structureless basement membrane. 

- 

^ J Connective tissue enclosing c-sbaped rings of hyaline 
] cartilage and secreting glands. 


1 
1 

Trachea. 


4. Three-coated tube. 


„ J Epithelium. 

1 Connective tissue base. 

2, -{ Muscle — one, two or three layers. 

1. ■{ Connective tissue. 


Epididymis. 


5. Four-coated tube. 


1 Epithelium. 
4. -i Connective tissue base. 

1 Muscle — one or two layers — muscularis mucosae. 

o ' Areolar tissue with blood vessels, nerves and lym-^ 
' ] phatics with or without secreting glands. 

2. -{Muscle — two or three layers. 

1. •{ Connective tissue. 


Pyloric stomach. 



Outlines.— The tubes of the body are constructed in outlines which 
are printed upon the two inside cardboard leaves of the model case. 
They are divided into ^ve classes and into non-motor and motor tubes. 
In the construction of all tubes a general tissue formula is employed as 
a matter of convenience. Each class of tube and each tube is constructed 
by building from the outside toward the center. The outlines exhibit the 
design according to which each tube is constructed. The words in italics 
call attention to those structures which characterize the organ. The 
numbers at the right are model numbers. It is thought that a design will 
create an incentive to build and induce one to demonstrate his personal 
conclusions concerning mechanical formations. An illustration of the 
outlines in their application to tubular structures may be seen in Plate 
XX which follows. 




PLATE XX. 
Outlines Applied to the Steuctural Foemation of the Five Tube Classes. 



63 



64 A CONSTRUCTIVE METHOD IN HISTOLOGY. 

Mechanics.— It is tliouglit that a knowledge of the simple principles 
of mechanics is essential to a clear comprehension of histological strnc- 
tures, tubular in character; for the very existence of tubes implies 
mechanical actions. The tubes of the body are flexible tubes and the flow 
of liquids through them is governed by certain natural laws. In sections 
for microscopic study the purposes of the structures seen do not appear 
and hence no particular reason for their occurrence is apparent. If, 
however, the mechanical possibilities of tubes are known the structures 
of which they are composed immediately become reasonable and conse- 
quently easily remembered. It is evident from the nature of tubes that 
they have contents and that the contents must, sooner or later, be set in 
motion. A tube without contents would be useless and also a tube with 
stationary contents would defeat the object of tubes as mechanical struc- 
tures. The contents of tubes necessarily implies the presence of some 
moving force. In any tube the motion of its contents may be due to a 
force from behind or to the walls of the tube itself or to both. On 
account of this intimate relationship between the tubes and their contents 
a division into non-motor and motor tubes is one of necessity and one 
that actually occurs. 

Non-Motor and Motor Ti(& 65.— Examination by means of the micro- 
scope reveals such a division. By a non-motor tube is understood a tube 
which is provided with no apparatus for setting in motion its contents. 
Contents are the products of chemical activities of those cells which form 
the linings of small tubes. Most of the small tubes which form the 
various viscera, in which a great variety of cell products is produced, are 
of this kind. A product must be formed before it requires removal and 
during its formation the force which arises from accumulation is 
sufficient to give it a start. After this some special motor power is 
necessary in order to convey it from its source to some other definite 
point. 

By a motor tube is understood any tube which is provided with some 
definite apparatus for the purpose of producing motion of its contents. 
All of the products of the viscera must be moved as rapidly as they are 
formed or the hydrostatic pressure of accumulation will of necessity 
check their formation. Hence the large tubes leading from the viscera 
have some form of moving apparatus. There are three varieties : muscu- 



THE TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT. 66 

lar-motor, ciliary-motor and muscular-ciliary-motor. In the muscular- 
motor tubes, muscle is tlie motor power and in most cases is smooth 
muscle. In the ciliary-motor, cilia of ciliated epithelium constitute the 
moving force and in the muscular-ciliary-motor both forms are employed. 
There is still another passive form of motion, as may be seen in the recoil 
of elastic tissue, but this is devoid of the active force which is exhibited 
by the other two forms. 

Knowledge of the non-motor and motor division of tubes serves a 
useful purpose in the estimation of their functional and structural capac- 
ities. When we study sections of tubes under the microscope we see 
them not as they occur in the living body but as they appear after they 
have been killed, fixed, hardened, stained and mounted on slides. Under 
these circumstances we are quite likely to think of them as inactive struc- 
tures serving the purpose of mechanical conduits whereas just the oppo- 
site is true. Tubes are living structures composed of living tissues and 
are always in a condition of activity. Their division into non-motor and 
motor tubes conveniently expresses their division into chemical and 
mechanical activities. Physiological division of labor accounts for the 
peculiar function of any organ. In the non-motor tubes, that particular 
form of physiological division of labor is present which results in the 
formation of a chemical product; while in the motor tubes it results in 
the mechanical expression of motion. This division, then, will enable us 
to think of the small, visceral, non-motor tubes as chiefly engaged in 
chemical activities and of the large, conducting, motor tubes as chiefly 
engaged in mechanical activities. 

Furthermore, this division enables one to locate two of the most 
essential tissues which enter into the formation of any tube, viz : muscle 
and epithelium. First, none of the small visceral tubes will have muscle. 
All the large conducting tubes (trachea and large bronchi excepted) will 
have muscle. The variety of muscle in nearly all cases will be smooth 
and arranged in one or two layers. This fact greatly facilitates their 
construction. Second, all tubes, great or small, will be lined by epithe- 
lium, the particular kind present depending upon its functional capacity. 
Motor or ciliated epithelium will not be found useful in tubes whose chief 
function is secretion or excretion and hence does not line the acini of any 
secreting or excreting gland. Neither will it be found in tubes whose 



66 A CONSTRUCTIVE METHOD IN HISTOLOGY, 

epithelium is osmotic, sueli as tlie alveoli of the lung and the vascular 
system. This leaves only a few places where it does occur, such as the 
larynx, trachea, bronchi, nasal ducts, uterus. Fallopian tubes, epididy- 
mis. Eustachian tubes and first part of the vas deferens. It is found in 
these tubes because their motor character requires it. The great major- 
ity of the visceral tubes of the body are, therefore, lined by epithelium 
whose functions are secretory, excretory, absorptive, non-absorptive and 
protective, and this epithelium is polygonal, polyhedral, columnar, tran- 
sitional and pavement. Secretory and excretory epithelium is polyg- 
onal, polyhedral and columnar ; absorptive is columnar and endothelial ; 
non-absorptive is transitional, and protective is pavement. This also 
facilitates tube construction as their non-motor and motor character 
enables one to decide what variety of epithelium is present. The classi- 
fication of the tubes of the body according to their non-motor and motor 
capacities is given in the outline which follows. 



THE TUBE AS A STBUCTUBAL AND FUNCTIONAL UNIT. 



67 



OUTLINE OF NON-MOTOR AND MOTOR TUBES. 



Kind of 
Tube. 



Motor 
Apparatus. 



None. 



Class of 
Tube. 



- One layer. 



Organs. 



1. Non-motor. -{ 



None. 



One-coated. 
Plate XXII. 



Tubes. ^ 



2. Motor. 



Muscular. 



Three-coated. 
Plate XXXTTI. 



Ciliary. 



Muscular 
ciliary. 



■ Capillaries. 

Tubuli seminiferi. 

Tubuli uriniferi. 

Crypts of Lieberkiihn. Gastric glands. 

Serous membranes. 

Graafian follicles. 

Small ducts. 

Skin. 

Hair follicle. 

Vestibule — utriculus — sacculus. 

Semi-circular canals. 

Cochlea. 

Nasal mucosa (olfactory part). 

Acini of secreting glands. 

Lacrimal sac. 

Vagina. 

Upper ureters, pelvis of kidney. 

Lower ureters. 

Urinary bladder. 

Gall bladder. 

Small artery. 

Small vein. 

Large ducts. 

Seminal vesicles. 

Urethra. 

Vas deferens (second part). 

Upper oesophagus. 
Lower oesophagus. 
Cardiac stomach. 
Pyloric stomach. 
Duodenum. 
Jejunum, Ileum. 
Large Intestine. 
Vermiform appendix. 



Two-coated. J Trachea. 
Plate XXVIIL ] Large bronchi. 

I Tympanum of ear. 
One-coated. J Eustachian tube. 
Plate XXIII. ] Nasal mucosa (respiratory part). 
1 Nasal duct. 

] Fallopian tube. 

Uterus. 
J Epididymis. 
Medium bronchi. 
Small bronchi, 
Vas deferens (first part). 



Contents. 



-( Liquid. 



Small liquid. 



Large solid and 
small liquid. 



Four-coated. 
Plate XXXVL 



Three-coated. 
Plate XXXIV. 



Large liquid 
and solid. 



Small liquid 
and large gas- 
eous. 



Small liquid. 



I Large solid and 
small liquid. 



68 



A CO:^8TRXJCTiyE METHOD ly HISTOLOGY. 



cox.STurcnox of tubft.^e 


OEGA2v5 BT JIOI'ELS. NUMBFR? AP.E MOIiEL NUMBERS. 




i 

OwGtAsa. 


OXB- 

Lla.tex 
Turk. 


ojte- o>"e- r— - 

Oo-i-TED Coated .'.j.zz.Z' 
Tdbk. Tube. IrBs. 


Tkske- 
Coated 

Tr2E. 


Thrrr- 

COATED 
TCBB. 


FCTB- 
Cl'ATED 


ITos- 

MOIOB. 

No. 


Moror.. ::;7:j, :::r;_- 
Nos. y>5. Vs. 




MrSCTTLAR 

Cn.IART- 

MoTCtR. 




r!iipillari^>^ 


J." 


J 








j 








Tnhnii ssrnninifcri 

SMiTMtJng glands : ThvTf.iVi , 1 

Parotid 

SulHnasillary and sublisgual _ 

Sub-ep^tlidjal _ „ 

Crypiis of LiebeikahD 

Pancreas _ 

Sweat glands 

Sebaraous glands _ 




'-[ --- 


iillllillii 
Mill! MM 


19-33 
19 30 
50 
19.45 
19.75 
ia50 
19.30 
19.50 
19.50 
19.50 
19.50 
19 90 
19.50 
19-30 
19.68 
19.^ 
19.49 
19.30 
19 30 
19.34 
19.75 
19.49 
19w30 
19.39 
78 
73.4S 
19.39 
L19.43.38 
2.37.22.21.46 
L34 A 1.63 
L68 A 1.63 

L64 
15.66 

1.65 
15l23 

1.77 








Meibonuan*glands „ 

rjM>hryina] g|j|nds 


Prostue gland „ . 

Cowper's glands 

I^abotMan glands . 


Bartbolin's glands .^...^,, .,..., ...._. 

OlandR of JAttr^ , 





Tnboli orinlferi : Neek _ .... _ 

Proxunal eonT<dation- 

Descending spiiaL. ., 

D^oending Rtraightu „ 

Henle''s loopu. 

Asoraiding s^Mral . .. „. 

Tm>gn1ar pnrtiAn 

Distal couToIoiion 

Junetional portion 

Duct of Bellini . 


Alrecrii of lung „ 

Graafian foUide 

1 Small dncts* 

; Hair follide 

Yestibale-atiicalas and saeeolos 

S^nieircalar eanals 

Cochlea 

T«^Tiin«l jqie 


i 


Nasal oUaetory maoosa 

Nasal duet^anier- 

Serods meailinuaeB 






Tjinpannni of <tar 






-- - 








/iasal dact, lower _ „ 

lifasal le^uatozy mueosa. „ 





j 15.36 

' _ _.!! 1.36 


^Tischea and large broncM 




32.;3.19.36 






Vas d^erei^ (2d part) 

Uppo' ureter 

Lower nrrter..... 

Urinary bladder i 

Yagina.- 

Artery-vein _ 

* Large lymphatie -..: 

Gall bladder 

1 Large duct 

.Seminal Tesides 

Corpus spongiosum 


' '■■ " 







1.&8l9.73.69 
l.S.9.73^ 
1 SL8.9l73u31 










La.8.9.73L31 
L9.12J0.S 


. — 








L1L35 

1.12.77 

L7.12.73L19L39 

1.7.12.73l19.39 

1.9.18.73L66 

L29.73L69A31 






....._........ 
















Medium brondius.. 




j 





53.8^73.19.36 

;L8L73-19.67 

, 1.7 11^73.36 A 69 

- 1.7.12.73.47 

11 s s a ?3 3i: 


Small broaehns 

Vaaa e^erentia of the testic3e 

EsididTmis _ 









1 Vas deferen.'i ^st part) 




..... 


1 Fallopian tube- 

; Uterus _ 








1.9.12.90L33 
1.5.10.9.m32 



TEE TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT. 



G9 



CONSTRUCTION OF TUBULAR ORGANS.— Cori^mMerf. 


Organs. 


One- 
Layer 
Tube. 


One- 
Coated 
Tube. 


One- 
Coated 
Tube. 


Two- 
Coated 
Tube. 


Three- 
Coated 
Tube. 


Three- 
Coated 
Tube. 


Four- 
Coated 
Tube. 


Non- 
Motor. 

No. 


Non- 
Motor. 

Nos, 


Ciliary- 
Motor. 

Nos. 


Ciliary- 
Motor. 

Nos. 


Muscular- 
Motor. 

Nos. 


Muscular 
Ciliary- 
Motor. 

Nos. 


Muscular- 
Motor. 

Nos. 


Upper oesophagus 














1.3.4.15.76.73.23 

1.9.8.15.76.73.23 

1.9.8.13.14.76.73.24 

1.5.6.14.76.73.25 

1.9.8.16.76.73.26 

1.9.8.17.76.73.26 

1.9.8.18.76.73.28 

1.9.8.20.7.27 


Lower oesophagus 












Cardiac stomach 






1 






Pyloric stomach 






i 






Duodenum 






1 






Jejunum ileum 






1 






Large intestine 






I 






Vermiform appendix 


















1 






EYE— ADAPTATION OF THE TUBE. 


Orgaics. 




One Coat. 
Non-Motor. 




Retina 

Cornea 

Coats of eye-ball 




54.55.56.57 
58.59.60.61 
44.19.51.2L3C 
70.71.72 


- 











We may consider the non-motor tubes first, as these are the simplest 
in structure and naturally become fundamantal in more complex forma- 
tions. The one layer and most of the one coated tubes belong to this 
class. 

One Layer Tubes, Non-Motor (see Plate XXI).— The one layer tube 
is composed of one single layer of pavement epithelial or endothelial cells 
united at their edges by cement. To this class of tube belong only the 
blood and lymph capillaries. On account of the single layer of cells 
forming their walls, they must necessarily be incapable of great strength 
and are therefore very short. They are also but little greater in diameter 
than the blood or lymph cells which pass through them. The blood capil- 
laries form those parts of the vascular system intermediate between the 
arteries and veins, and here it is that the processes, by which nutrition 
is maintained, are carried on. 



70 



A CO'NSTRUCTIYE METHOD IN HISTOLOGY. 



.l^s.^o 




vein. 

hll'35 



i-ihss- 



Oh^ iau^i- iiii^s. ho n- motor. 



CaAt 






PLATE XXI. 



A Smat.t. Poetion of the Cieculation Showing a Small Abteby, Capillaby Plexus and 
Small Vein. (Numbers in all plates are model numbers.) 

The single layer character of the walls of these tubes adapts them to 
the osmotic or secretory conditions, as the laws of osmosis and secretion 
require very thin animal structures between interchanging liquids. 
"Whatever passes out of the blood or into it must pass through this ex- 
tremely short portion of the thinnest part of the circulatory system. 
Anything more than a single layer of pavement cells in the structure of 



THE TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT, 



71 



these tubes would defeat the whole process of nutrition and elimination. 
Since it is the simplest variety of tissue which is found in the body and 




PLATE XXII. 

Thiety-one One-Coated, Non-motor Tubes in one Diageam, Showing Layers Common to 

THEM ALL. (Numbers are model numbers.) 

has a definite function, it may be taken as a fundamental type of tube 
formation. It does not follow from this that the same kind of epithelium 
must form the lining of all tubes ; but that some form of epithelium must 



I 2 A COS STRUCT IT E METHOD IX HISTOLOGY. 

be found there. To this may be added other tissues for protection, sup- 
port, vascular supply, motion and fonn, and the remaining four classes 
of tubes may be constructed. (See Plate XX, fig. 40, for the capil- 
lary, and the remaining figures of the same plate for the construction of 
other tubes : also case outline of a one layer tube.) 




PLATE XXni. 

FouE 0>t:- Coated Celiaey Motob TrsES i:s Oxe, Showing Layees Common to them att.. 

(Xuinbers are model numbers.) 



One Coated Tubes (Xon-Motor and Ciliary Motor) (see Plates XXII, 
non-motor ; XXJH, ciliary motor— mic. and XXTV, XXTV, XXYI— mac). 
— The next form or class of tube, somewhat more complex in formation 
and function than the one laver tube, is the one coated tube. It may be 
f onned from a one layer tube by adding directly to its outer aspect some 
other varieties of tissue. In the construction of this tube from a one 



TEE TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT. 



73 



layer tube a general tissue formula is employed and not a special or 
restrictive one; that is, the one layer tube is understood to be not an 
osmotic or absorptive tube restrictively but a tube of any function which 
gives character to the organ by virtue of its own particular epithelium. 
It has two layers, one epithelium and the other some variety of connec- 
tive tissue. 

The epithelium may be of any variety and the connective tissue may 
be in the form of a basement membrane, structureless in character or in 
the form of areolar tissue or base, containing blood vessels, nerves and 
lymphatics, with or without secreting glands. These tubes are, for the 
most part, small and constitute the structural units of most of the vis- 
cera. They are joined by connective tissue and form such organs as the 
kidneys, testicles, ovaries, secreting glands and lungs, or they may be in 
large expanded areas as in the skin and serous membranes or they may 



il9-3o. 




g'Cay\c{ 



19-So. 
Simjife SacaUaf inland 



duct. 

' J9 



ciHui 




19-S-O 



Hacemcsz or Cothiouncl 




Ii-7S 



li'3f. 







LoixuLa of -thz^ancruS- Srn(\H j^ortLCncf tke lnan}n\a\'y flan<( 



OMCoatid iut^i. non-Tnoioi'. Sccreftny fCan(<s~actni 

PLATE XXIV. 

Types of Secreting Glands, 



74 A OOWgrSU^fTVE MI7'£ . 

be in iiie form of a prolonged r tH ^ t ' in a bony canal as in ilie 
internal ear. At first ^ong^ it na ~ ttH ^ : —hat confusing to asso- 
ciate as belongbig to flie same C- :-.. - - : : : : i ? :: ; _ ^ ractares as Ute acini 
of secrefing glands^ internal ear _ £ z ; bnt if we consider ibem from 
file ^viewpoint of Unear fonctionE . : £^, we shall see tiiat ibe first 

are seereling organs, ^diile flie '.?..'-: - :r 5t£ :ry. The str u ctura l 
reqinreafents of tibese two classes of organs air — - tiaHy &e same; 
fliat is, tibe functionating part nmst be as near to the blood corrent as 
possible. This tjpe of tobe, tJieref ore, is adapted by strncture to fonc- 
tions of secretion and special sense. Secreting glands are all oonstrocted 
on the same plan, inzi a basement membrane witii a circalation on one 
side of it and some variety of epitbelinm on the otiiier. This arrange- 
ment brings fte fonctional ^nflieliTin ?^ near to tiie blood stream as it 
is possiUe to get it. It is as eE-T:i~: - :iiat nenro-epiOieliam shonld be 
dose to the blood stream as it is mai ^^^reting epitbelinm shonld be, for 
an bi^^ily organized cells reqmre siich pc^?:tions. To Ibis dass of tube 
bdon? cbiefly the seerefeg- organs and Ul^ organs of special sense, as : 

5: -■-:■":■-:, Semaory: 

-'lyi-i 'inz-ii'T:: :it £iiii~^, ITcBtibalei^ wtricali, taxcu-i. 5-rn:::7:i_ir 



Under :'-r —Lzroscope a smaD, simple, isolated tube in crc 
is n:: ? e?^:.- i fentrSed as fbe large comfdex one; for exar 
di~,ul: :: n : : li_ : : V to identify in cross section the as : i 
tion of Eenie s . : he Hdney or a blood capDary if ±e 

served ty :leii e "r - — ::1 : i : reference to adjoining jiarts, wtL\i 
tification :: :'-- :-- £_ r:s ":ems or artery is a simple ma:: 
is, in order : : e r : s Ij : - : : riLz- i voider fee microsoox>e, any : : 
have a sn£ ien: n :zaber of tissues arranged according to a :e: 
l^an, to r"r :'-?.: r^an a distinctive diaraeter. This arrange 
la :: e ' ~:~a :ae a ?t of recognition iiian a sin^e cell : 

""r - - a: T ; ae kidney tnbe or secreting g^and a jina 
5^ : a a: a_aa7 :: :_ !_ aaJted by connective tissue, so :1a: 



L_e 



THE TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT. 



76 



SENSORY SYSTEM. 



Organ. 



DiVISIOKS. 



1. External 
ear. 



Subdivisions. 



Further Divisions. 



1. Pinna. 



2. Externalj 
auditory canal. 



3. Membrana 
tympani. 



1. Skin. 
-! 2. Glands. 
I 3. Connective tissue. 

1. Skin. 

2. Cartilaginous part. 

3. Glands. 

4. Bony part. 



1. Lamina propria. 



2. Cutaneous layer. 



3. Mucous layer. 



Structure. 



•{ Like the structure of skin elsewhere. 

•{ Sebaceous in character. 

■{ Like any subcutaneous tissue. 

■{ Same as elsewhere. 

■i Yellow elastic. 

■{ Sebaceous, ceruminous. 

Connective tissue fibers 
radiating from the peri- 

1. Outer layer, -i phery of the tympanum 

to the attachment of the 
head of the malleus. 

2. Inner layer. ^ Coooective tissue fibers 
oozu^x xaj-c . -^ running circularly. 

■{ Like skin elsewhere except that it is thinner. 
1. White fibrous tis- 
1. Tunica propria. 2.^ 2. Yellow elastic tis- 
sue. 



2. Epithelium. 



1. ■{ Polyhedral cells. 



3. Ear. { 



2. Middle 
ear or tym--= 
panum. 



1. Wall of the 
tympanic cav-< 
ity. 



1. Bone and periosteum. 



2. Mucous membrane. 



1. Tunica pro- J A tissue resembling lym- 
pria, ] phoid. 



2. Epithelium. 



3. Glands. 



Polyhedral cells over the 
ossicles, simple pseudo- 
stratified ciliated else- 
where. 

< Tubular. 



2. Mastoid cells. 



1. Bone and periosteum. 



2. Mucous membrane. 



I 1. Mucous membrane. 
3. Secondary I 
tympanic mem-^ 2. Lamina propria. 



brane. 



3. Endothelium. 
1. Incus. 



4. Ossicles or! 2. Malleus, 
ear bones. ] 

3. Stapes. 



5. Eustachian, 
tube. 



1. Framework. 



2. Mucous membrane. 



J 1. Connective tissue. 
) 2. Polyhedral epithelium. 

J 1. Connective tissue. 

) 2. Polyhedral epithelium. 

<( Connective tissue. 

^ AnviL 

-{ Mallet. 

-{ Stirrup. 

J 1. Bone. 
I 2. Cartilage. 

1. Tympanic. 

2. Laryngeal. 

3. Bony part. 



J 1. Connective tissue. 
] 2. Ciliated epithelium. 

J 1. Connective tissue. 
] 2. Columnar epithelium. 

J 1. Connective tissue. 
] 2. Cubical epithelium. 



76 



A COySTRUCTITE METHOD IX HISTOLOGY. 



SEXSORY SYSTESL— Continued. 



OsGAif. Dmsioxs. Description. Divisions. 



Subdivisions asd Stbuctuee. 



1. Bonr 



Outside bony 
wall of tlie 



labyrintli. "> whole inter- 
nal ear. 



Inter- . 
nal ear."^ 



2. Perilym- 
p h a t i c ^ 
space. 



1. A tapering bone tube wound, spirally around an axis or modiolus, 

j Central, small, triangular canal I 1. Tunic of wliite fibrous 

2. Ductus coch- I attached by base to the outer | tissue, 

learis or scala<; wall of bone tube and by the-^ 2. PaTement epithelium. 
media. opposite border to the spiral 3. Cubical epithelium 

1 lamina. | partly. 

3. Scala vestib- J Superior division of i)erilym- J 1. Periosteum as a base, 
uli. 1 phatic space, ] 2. Endothelium. 

4. Scala t y m- J Inferior division of perilym- J 1. Periosteum as a base, 
pani. ] phatic si>ace. | 2. Endothelium. 



'<^Fe^^sneT ^'\ ^® ^^® **^ ductus cochlearis. -l 2. Connective tissue base. 



I 1. Endothelium. 

2. Connective tis 

3. Polyhedral epithelium. 



6. Basilar mem- . The other side of the ductusj ^ Cells of SnSii 
) co(^earis. j 



brane. 



3. Cells of Qaudius, 



. Crista basi- 
laris. 



Ridge to which basilar mem- 
brane is attached. 



L Cochlea. ■{ 



^'laris.* ^^^^'^ A richly vascular structure. 
9. Ductus coch- J L Limbus. 



Space between 
bony laby- 
rinth and 
membranous-^ 
lab vrinth 
filled' with 
liquid. 



3. Trabecu- 
Ije. 



Prolongations 
from the 
periosteum 
of the outer 
bony wall ex- 
tending be- 
tween that 
wall and the 
central mem- 
branous tube. 



leans. 



10. Organ 
Corti. 



~1 2. Basilar membrane. 



of 



1. Zona, tecta 
or inner 
zone. ^ 

2. Zona pecti- 
nati or outer 
zone. 



1, Epithelial 
arches. 



W Thickened periosteum. j 

J Epithelium on both sides of 
I blood vessels. 

1 1. Thick periosteum. , 

I 2. Jxeuro-epitheLium. I 

^"A^^'MilJ Nmro-epithe- 



2. TunnelsJ Space beneath I Filled with 
of Corti- "l the rafters, ] semi-fluid. 



a PUlars, -^ 



L Inner — 
short 



5,600 in num- 
ber. 



2, Outer— 13,850 in num- 
long. 1 ber. 



11. Hair cells | 1- Inner, 
within the 
arches of^ 
Corti. I 2. Outer. 



r<! 



Columnar bodies with oval nuclei and granular 
protoplasm from the outer ends of which project 

20 hairs. 

Three or four rows of columnar cells, with ex- 
panded, rounded ends from which project 20 hairs. 



2, Vesti- 
bule, 



1 1, Epithelium ending in end plates and resting upon basilar 
12. Cells of Dei-J membrane. 

ter. I 2, Long, columnar cells with spherical nuclei and pyramidal 

I ending, 

I 1. White fibrous tissue, 

2. Polyhedral epithelium except over the maculae cribosae and 
1 acusticae. 
1. Anterior _j 3. Macula cribosa. J Regions receiving ends of auditory 

saccule. i 4. Macula acustica. ; nerve. 

5. Sustentacular cells — ^pigmented. 
I 6. Hair I Columnar, pigmented cells with spherical nuclei and 
' cells. 1 a single hair projecting from the free ends. 

""ivmphatlcus 'i ^ ^^'^ between the saccule and utricle. 

3. Posteriori Larger than the saccule — same in structure. Has the five 
utricle. ) opening? of three semicircular canals. 

4. Otolith mem- 1 Membrane of otoliths, ear stones or crystalline bodies em- 
brane. i bedded in a soft gelatinous substance covering the free sur- 
orane. | ^^^^ ^^ ^^ neuro-epithelium of the saccule and utricle. 



TEE TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT. 



77 



SENSORY SYSTEM.— Continued. 



Organ. 



Inter- 



Divisions. 



4. Mem- 



Description. Divisions. 



Central mem- 
branous tube 



nalearj PJwi^^L ^ of the whole ^ 



labyrinth. 



internal ear. 



3. Semi- 
circular 
canals. 



4. Auditory 
nerve. 



Subdivisions and Structure. 



1. External. 

2. Superior. 

3. Posterior. 



1. Vestibular. 



2. Cochlear. 



Begin and 
end in the* 
utricle. 



1. White fibrous tissue base. 

2. Polyhedral epithelium. 



3. Am- 
pulla. 



Dilated parts 
near the en- 
trances to 
the utricle. 



Crista 
acus- -^ 
tica. 



Areaofneuro- 
epith e 1 i u m 
as a percep- 
tive appara- 
tus like other 
similar parts 
in structure. 



1. Branches communicating laterally with the spiral canal of 
bony lamina. 

2. Radiating bundles extending to the neuro-epithelium. 



of the one coated tubes is built up with the models it does not seem to 
resemble the pictures of the text books or of the microscope. It is only 
necessary, however, to isolate one tube of the microscopic picture for 
comparative study. In fig. 40, of Plates XYII and XX, the blood 
capillary is represented longitudinally and not in cross section for the 
reason that a simple pavement epithelium or endothelial cell in cross sec- 
tion is not recognizable on account of its extreme thinness. The one 
layer and one coated tubes, with few exceptions, do not have a motor 
apparatus because none is required. In the secreting organs they con- 




One-Coated Tube. 



PLATE XXV. 
Non-motor. Membranous Labyrinth of Internal Ear. 




Ohe COo.±e(Hutre.i-y\or\-lir\otor- 



PLATE XXVI. 

DiAGBAM Showing Kidney Tube and its Connection with the Cibctilation. 

(Numbers are model numbers.) 



78 




PLATE XXVII. 



Theee-coated Tubes — LIedium and Small Bronchi — Musculae-Ciliary Motor. 
COATED Tubes Larynx, Trachea, Large Bronchi — Ciliary Motor. 

Respiratory System. 



Two- 



79 



80 



A CONSTRUCTIVE METHOD IN HISTOLOGY. 



stitute the manufactories of the body secretions and excretions which do 
not need a moving apparatus until the products are formed and forced 
away from their sources by the force of accumulation. (See Plate XX, 
figs. 19 and 50, and case outlines of one coated tubes ; also Plates XXIV, 
XX^^ and XXVI.) 







' t-ach^a 



PLATE XXVIII. 

Two Two-coated Ciliaey INIotor TrBES ix 0^"E, Showing Coats a^td Layebs Common 
TO Both. (Numbers are model numbers.) 



Two Coated Tubes, Ciliary-Motor (see Plates XXVII and XXVTTT), 
— A two coated tube is formed by adding to a one coated tube "C 
shaped rings of hyaline cartilage which are enclosed in the outside con- 
nective tissue coat, which has also secreting glands. To this class of 
tube belong the trachea and large bronchi. 

The characteristic difference between this tube and the one coated 
tube is in the presence of the cartilage rings (see Plate XXV HI). The 
essential requirements of this class of tubes are two ; that they constantly 
be kept open and that their very small liquid contents be moved towards 
the upper end. The first requirement is met by the cartilage rings, the 



THE TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT. 



81 



second by cilia. A muscular coat is unnecessary. Between the ends of 
the rings a very little smooth muscle is found, arranged in longitudinal 
and transverse layers. This muscle, however, evidently takes no part in 
the propulsion of the contents. The two coated tubes are therefore 
ciliary-motor. (See Plate XX, figs. 52, 73, 19 and 36, and case outline 
of two coated tubes.) 

Three Coated Tubes, Muscular-Motor and Muscular-Ciliary-Motor 
(see Plates XXVII, XXIX, XXX, XXXI, XXXII-mac, XXXIII, 
XXXIV— mic.).— These tubes are mostly large and visible to the naked 






Q^oy 




Theee-coated Tubes. 



PLATE XXIX. 

VaGINxV — ^MUSCULAE MOTOE. FALLOPIAN TUBES AND UtEEUS, 

muscxrlae-ctliaey motoe. 
Female Genital System. 



eye. They may be formed from a two coated tube by taking out its 
cartilage rings and adding one, two or three layers of smooth muscle in 
the form of a coat. The two coated tubes are the only ones the diameters 
of which must of necessity remain unchanged and hence the only tubes 
having cartilage rings. They may be looked upon as unique tubes pro- 
vided with one variety of connective tissue for the special purposes of 



82 



A COySTRVCTITE METHOD IN HISTOLOGY. 



one location and the cartilage rings can be removed withont essentially 
changing the character of tnbe formation. It is thonght best to separate 
the trachea and large bronchi which are ontside the Inngs from the 
medium and small bronchi which are inside the lungs, because structur- 
ally and functionally they differ so widely from each other. The trachea 
and large bronchi are simply open tubes for the free income and outgo 
of air, their constantly o^Den character being the essential one ; while the 
medium and small bronchi are open tubes kept open by over-lapping 
cartilage plates, and subject to changes in diameter according to the res- 
piratory requirements. The volume of air in the trachea and large 
bronchi must always remain about the same, while in the medium and 
small bronchi it must be subject to control according to variations in the 
oxygen income. Therefore, the trachea and large bronchi are open carti- 
lage tubes incapable of changing their diameters by means of a muscular 
coat, while the medium and small bronchi are open cartilage tubes capa- 
ble of changing their diameters by means of a muscular coat. 
The organs which belong to the three coated tubes are : 



Medium and small bronchi. 

Arteries, 

Veins, 

Large lymphatics, 

Large ducts, 

Grail bladder. 



Fallopian tubes, 

Uterus, 

Vagina, 

Vasa-efferentia of testicles. 

Epididymis, 

Vas deferens. 

Seminal vesicles. 

Ureters, 

Urinary bladder, 

Urethra. 



These tubes are muscular-motor and muscular-ciliary-motor. They 
are adapted to a progressive or intermittent motion of their contents and 
hence some have muscle, others cilia and muscle. The muscular coat 
may have one, two or three layers. The uterus, vas deferens, lower 
ureters and bladder have three layers. The Fallopian tubes, vagina, 
epididymis, seminal vesicles, upper ureters and large ducts have two 
layers. The arteries and veins have one layer. 



Right Int. jugular vein 
Right com, carotid artery 

Right sub-clavian vein 
Sup. vena cava 

Pulmonary artery 

Heart 

Thoracic duct 
Hepatic vein 

Liver 

Hepatic artery 

Gastric vein 

Portal vein 

Renal vein 

Renal artery 

Kidney 

Inf. vena cava 

Large intestine 

Small intestine 



Small vein 
1-11-35 




Left int. jugular 
Left com. carotid 
Left subclavian artery 

Arch of aorta 
Pulmonary veins 

Lung 

Oesophagus 

Stomach 
Spleen 
Splenic artery 

Splenic vein 
Sup. mesen. vein 
Aorta 

Mesenteric artery 
Mesenteric vein inf. 

Lymph vessels 
Mesenteric gland 



Capillary 40 

Small artery 1-11-35 



PLATE XXX. 

Diagram of the Circulation. 

Three-coated tubes — ^]\Iuscular motor. One-layer tubes — Capillaries non-motor. Modi- 
fied muscular motor tubes — ^Alternating layers of elastic tissue and smooth muscle — ^Large 
blood vessels. 



83 



84 



A CONSTRUCTIVE METHOD IN HISTOLOGY. 



In the bladder a hydrostatic pressure is exerted in all directions and 
hence it requires a muscular coat acting in all directions. 







i-S-^^i-i/, 






,skn% Mm 










,eCi<. 



^ 



PLATE XXXI. 
Thbee-coated Tubes — ^Mtisctjlab-motob. Pelvis of Kidkey-ubeteb-bladdeb. 



The larger blood vessels do not have the definite coat, but have smooth 
muscle and elastic tissue intermixed. 

The Fallopian tubes, uterus, epididymis, first part of the vas defer- 
ens, medium and small bronchi have both muscle and cilia, hence are 
provided with two sets of motor apparatus. The presence of a muscular 
coat in the walls of tubes shows that their contents may be large and 
continually or intermittently in motion and that considerable force may 
be required to move them. The presence of cilia in the walls of tubes 
shows that their contents may be very small and continually in motion 



Tunica Adru^inQQ 



Tumult . 
€ti-0Tna 




TM^ccufae 



"^^•^-^r/noYil-^ 



PLATE XXXII. 

Three-coated Tubes. Muscular-ciliaey-motor. 

Epididymis, globus major, globus minor and first part of vas deferens. Muscular-motor, 
Second part of vas deferens. Vasa efferentia have alternating patches of muscular-ciliary 
and muscular-motor structures. One-coated tubes — Non-motor, tubuli seminiferi. 



85 




PLATE XXXIII. 

Twelve Theee-coated Musculae Motob Tubes in one, Showing Coats and Layebs Common 
TO THEM ALL. (Numbers are model numbers.) 



86 



THE TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT. 



87 



and that very little force is required to move them. The presence of 
both muscle and cilia shows that the contents may be large and moved 
with difficulty or small and easily moved. The circulatory tubes differ 



7 ! 1:^^3Ck:»s=Sj!;^:^^:S>&J53E 




PLATE XXXIV. 

Seven Three-coated Musculae Ciliaby Motor Tubes in One, Showing Coats and Layers 
Common to them all. (Numbers are model numbers.) 

from other tubes in this respect; that their contents are propelled by a 
force from behind and hence a distinct muscular coat is unnecessary. 

The epithelium varies in kind according to the location of the tube, 
nearly all varieties being found. In one instance, the medium bronchi, 



88 A CONSTRUCTIVE METHOD IN HISTOLOGY. 

the outside connective tissue coat contains plates of hyaline cartilage. 
Secreting glands are found only in the urethra, cervix uteri, medium and 
small bronchi and possibly vagina. (See Plate XX, figs. 1, 7, 12, 73 
and 47, and case outline of three coated tubes.) 

The eye ball is a modified adaptation of the three coated tube. Its 
diameters being equal, the organ is nearly spherical. It is a combination 
of the segments of two spheres of different curvatures. It is not a motor 
tube and, therefore, has no muscular coat. The three coated tube ar- 
rangement, however, is still preserved. (See case outlines of three 
coated tubes.) 



THE TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT, 



89 



SENSORY SYSTEM— Continued. 



Organ. 



Divisions 



1. Cornea. ■ 



Description. 



The anterior 
tran s p a r e n t 
one-sixth part 
of the eye ball. 



Subdivisions. 



1. Anterior epithe- 
lium. 



Structure. 



-| Stratified pavement epithelium. 



2. Anterior limiting I 
membrane, mem— j A highly developed basement membrane, 
brane of Bowman. 



3. Substantia 
pria. 



Parallel lamellae of interlacing bundles of fibrous tis- 
P J sue united by cement. Branched connective tis- 
sue cells and wandering cells. 



4. Posterior limit- I 
ing membrane,! 1. A clear homogeneous basement membrane. 



membrane of Des- 
cemet. 



2. Endothelium. 



^' ifum*.^^^^^ epithe- J ^ gj^gjg j^^gj. ^^ polyhedral epithelial cells. 



2. Sclera, 



Lamina 
fusca. 



^" hill. < 3- Lamina 
supra- 
choroidea. 



The posterior 
opaque five-^ 
sixths part of 
the eye ball. 

The rough,! 
brown, innerj 
surface of the | 
sclera. I 

A thin mem- 
brane loosely 
united to the* 
lamina fusca 
and choroid. 



1. Cells. 

2. Base. 

3. Cells. 

1. Base. 

2. Cells. 

1. Base. 

2. Cells. 



■{ 1. A single layer of flattened epithelial cells. 

J 2. Interlacing bundles of fibrous tissue extending 
I meridionally and equatorially. 

■{ 3. Single layer of flattened epithelial cells. 

•{ 1. A pigmented connective tissue. 
-{ 2. Endothelium. 

J Imperfect lamellse of a fibro-elastic ground work 
1 joining at various angles. 



-{ Irregular groups of endothelial cells 
1. Outer layer 



4. Choroid. 



5. Ciliary 
body. 



A dark brown 
membrane be- 
tween the" 
sclera and 
retina. 



The part be- 
tween the end 
of the chorio- 
capillaris op- 
posite the ora^ 
serrata behind 
and the outer 
margin of the 
iris in front. 



1. Stroma layer. 



2. Chorio-capillaris. 



1. Branched pigmented cells. 

2. Connective tissue lamellse. 

3. Large blood vessels. 

I Unpigmented wavy bundles of 

2. Inner layer. -< connective tissue giving a metal- 

I lie reflex called tapetum fibrosum. 

A narrow zone of homogeneous matrix in which is 
embedded a capillary network from short ciliary 
arteries. 

3. Vitreous lamina. J ^^^.^^' homogeneous layer supporting the retinal 

1. Ciliary ring or 1 1. White fibrous tissue, 
orbicularis cili-J 2. Yellow elastic tissue. 

aris. I 3. Smooth muscle prolonged from the ciliary muscle. 

2. Ciliary processes, I l' ^''■1%''''^ ^^^^T Pig«»ented epithelium, 
seventv in niim J 2- Middle connective tissue layer. 

ber 1 ^- Smooth muscle arranged meridionally, radially 

j and circularly. 

1. Smooth muscle arranged meridionally, radially 
Q piiiaTiT mno^io J and circularly. 

6. v^iuary muscie. ■<; ^ Connective tissue interlacing with the smooth 
muscle. 



90 



A COXSTBrCTITE METHOD IX HISTOLOGY. 



SENSOET SYSTEiL- 



0KGA2f. DESCKIPTIOX. 



6u Iris 

of the 

eye. 



Dmsioxs. 



1. Anterior ■ 

endothelium. ^ 



2. Anterior 
boundary-^ 
layer. | 

I 



DSSCKIPTIO^f. 

Extension of 
the corneal 
cells free from"' 



ScBDmsioxs. 



STErcmrRE. 



L CeUs. 



pigment. 

Jlodifieation of I 
the first stra-J 
turn of the] 
iris stroma. I 



2. Base. 



Single layer of polygonal, nucleaied, 

epithelial cells. 

-{ Cement. 



i 



L Cells. 
2. Base. 



3.Ta5CTilarJ CSuef mass of^ 
stroma layer.l the iria. 



1. Stroma. 



2. Masde. 



3. Kerves. 



The contrac- 
tile colored 
membrane 
« behind t h e ^ 
cornea gir- . 
ing the tint 
to the ere. 



-L Posterior ' 

boundary<; 
laver. * i 



5. Pigmsited 
layer. 



Glassy layer] 

stretching orer ; 
the posteriori 
surface of the ■ 
stroma. 



A layer cover- 
ing the entire 
pupillary mar- 
gin ending as a 
thickened free^ 
edge in ad- 
ranee of the 
plane of the 



\ L«icocTtes. 

^ Eetictilar tissue. 

J Eetiform tissue reinforced by blood 

; Tessels. 

-{ Smoodu j 

J Medullated in the superficial part, non- 
1 medtillaied nersrorks within. 

j The arteries spring from the circulus 
I arteriosus iridis major, pass radially 
•4. MoodTesae3&^ toward the center of the iris neair 
I vhidi theyjform a second ring called 
I the dreulus arteriosus iridis minor. 

5. 5 p h i n c t e r i Smooth muscle surrounding the margin 
pupillse. I of the pupiL 

jjg^ ^'^P^P""^ Smooth musde radially arranged. 



b a 5 e m en t^ Though stmcrureless. it closelv resem- 
mei^brane. 1 ^^^ ^^^^^ ^^^ ^ character. 



Spindle cells zadlallT arranged, extend- 
ing frova. the ciliary border of the 
iris to the margin of the pupiL At 
the ciliary boitier the eeUs" change 
their form to polyhedral and are con- 
tinuous with the low pigment cells 
composing the corresponding layer of 
the ciliary processes. 



1. Anterior part^ 



2. Posterior 
part 



A thick rone of pigment cells so densely 
packed that their boundaries and 
nuclei are very indistinct, tliei^ole 
resembling one continuous mass of 
pigment A delicate membrane — the 
membrana limitans iridis — covers the 
pceterior surface. 



6. Pupa 



I Circular in 

, . . ^^ ' form, a little 

Apertnre m the , to the inner 

^ center of the< g^e of the 

I ^^^^ center of the 



1. Blue eyes, -| Stroma free from pigment. 



The color of the 
eye depends 

•» r<»i/v* «*• upon thei 

'vil® ° -< amount and" 3. Brown eyes, 

kind of pig- 
ment in the 
iris. 



^ e^^* ^^^^< Pigment in small amount 



Iris. 



Pigment in large amount. 
4, Black eyes. -■ Pigment in rery lai^ amotmt. 



5. Albino eres. 4 -^9 pigment eren in retinal part of the 
I iris. 



THE TUBE AS A STRUGTUBAL AND FUNCTIONAL UNIT. 



91 



Okgan. 



SENSORY SYSTEM!.— Continued. 



7. Retina of 
the eye. ■ 



Dksckiption. 



Divisions from 
Within Outward. 



Description and Structure. 



Radial fibers of Miiller. 



1. Internal limit i n g 
membrane. 



2. Layer of nerye J 
fibers. I 



Long neuroglia fibers extending throughout the en- 
tire thickness of the retina. 

Expanded inner ends of the radial fibers of Muller 
forming the inner boundary of the retina next to 
the vitreous humor. 

Axis cylinders of the optic nerve fibers which extend 
as far forward as the ora serrata. 



3. Layer of nerve cells. ■{ A single sow of multipolar large nerve cells. 



4. Inner molecular 
layer. 



A delicate mem- 
brane containing 
the expanded ter- 
mination of the 
optic nerve. It is 
within the cho- 
roid, rests on the 
hyaline mem- 
brane of the vitre- -j 
ous humor, ex- 
tends forward to 
the outer edge of 
the ciliary proc- 
esses of the cho- 
roid where it ends 
in a border called 
the ora serrata. 



5. Inner nuclear layer. -| 

6. Outer molecularl 



layer. 



7. Outer nuclear layer. J 

8. External limiting J 
membrane. | 



9. Layer of rods. 



Reticular tissue of the neuroglia, branches of nerve 
cells and a few flattened cells. 

An inner layer of small multipolar nerve cells and an 
outer layer of small bipolar nerve cells. 

Reticular tissue of neuroglia and branches of nerve 
cells. 

Rod granules and cone granules according to their con- 
nection with the rods or cones. 

Structureless membrane formed by the expansion of 
the outer branched ends of the fibers of Muller. 

1. Outer J A series of transverse disks which are 
segment. ) the seat of the visual purple. 



10. Layer of cones. 



2. Inner 
segment. 



1. Inner 
segment. 



I 1. Rod 
I fibers. 

2. Rod 
granules. 

1. Cone 

fibers. 



Protoplasmic bodies of the 
visual cells. 

Seat of the nuclei of the 

visual cells. 

Like rod fibers except that 
they are broader and 
more regular in form. 



^' granules, i ^^^ *^« ^«^ g^^^"^^^' 



2. Outer 
segment 



A 



A series of transverse disks. 



11. Pigment layer. 



A single layer of hexagonal epithelium. The outer 
surface of each cell contains the nucleus. The inner 
boundary is not well marked for the substance of 
the cell is here loaded with black pigment and pro- 
longed into fine straight? filamentous processes 
which extend a certain distance between and among 
the outer segments of the rods and cones. 



92 



A CONSTRUCTIVE METHOD IN HISTOLOGY. 



SENSORY SYSTEM..— CcnHnued. EYE. 



DlVISIO>fS OF THE j 

Retina a^d Other j 
Parts of the Eye. ; 



DESCRIPTIOif. 



1. Macula lutea. 



2. Fovea centralis. 



3. Ora serrata. 



Divisions. 



An elliptical yellow ^ 
spot situated in , ' 
the axis of the [ q 
eye ball. | ' 

A slightly hollow I 
place in the center J 
of the macula] 
lutea. I 



Structure. 



Border. ^ Yellow pigment, retinal layers. 

Center. ^ See fovea centralis. 



1. Layers of retina except the rods. 

2. Black pigment layer. 



4. Optic nerve. 



5. Crystalline lens. 



6. Aqueous humor. 



The anterior border 
of the retina sit- 
uated just behind-; 
the ciliary proceS' 
ses. 



The cerebral nerve 
which enters the 
eye ball % of an< 
inch to the inside 
of the axis. 



A double, convex, 
transparent, solid 
body with the an- 
terior surface in 
contact with the"* 
iris and posterior 
surface with the 
vitreous body. 

A watery lymph, 
which fills the 
aqueous chamber 
between the lens 
and cornea. 



, End of the 
optical retina. 

, Serrated edge. 

, End of the 
two reticula 
strata. 

, Unusual de- 
velopment of 
radial fibers 
of Miiller. 

, Connective 
tissue sheath. 



1. Pars ciliaris. «( Outer layer. 



Extension of the 
retinal pigment 
only. 

Simple columnar 



2. Pars iridica. H Inner layer. ^ ^^^jSlheliim 



1. Dura mater. 

2. Arachnoid. 

3. Pia mater. 



Trunk. «j Bundles of medullated nerve fibers without neurilemma. 

I 

i 



g * A '^ u s ^ Connective tissue divisions between the nerve fibers, 



1. Lens fibers. •{ Greatly elongated epithelial cells. 

2. Lens epithelium. ■{ Single layer of polyhedral cells. 
Lens capsule. ■{ A strong, clear elastic membrane enclosing the lens. 



Lens sub-J 
stance. | 



A spherical gelatin- 
ous body filling 
four-fifths of the 
7. Vitreous humor.^ eye ball and ex-^ 
tending from the 
retina behind to 
the lens in front. 



n^mbrane^ ^ Glassy, structureless membrane around the outside. 



8. Eyelids. 



Two movable por- 
tions of integu- 
ment covering the' 
eye ball. 



, Patellar fossa.-] 

. Vitreous sub- 
stance. 

. Central canal. -^ 

, Skin. ^ 

, Muscle. ■{ 

. Conn e c t i V e J 
tissue. 1 

, Tarsal plate. J 
, Conjunctiva, -i 



Space in front where hyaloid membrane is absent and 
anterior surface touches posterior capsule. 

1. Fibers. -{ Connective tissue fibers of great delicacy. 

2. Cells. -( A few leucocytes. 

A canal extending from the optic papilla to lens capsule. 
Like integument elsewhere. 
Orbicularis palpebrarum. 

1, Tendon of the levator palpebrae. 

2. Fascia palpebralis containing smooth muscle, 

1, Semilunar plate of dense fibrous tissue. 

2. Meibomian glands. 

1, Epithelium, stratified pavement, 

2, Tunica propria of connective tissue. 






^l-f-il-/5 7-?i-iJ. 




CaydidC 

Stomach 



CoiOri 



^-1j-«S7i/iJ» 



;3' 






Atjus 

PLATE XXXV. 
FouB-coATED TuBE-MUSCULAK-MOTOR — ALIMENTARY Canal. (Numbers are model numbers.) 



93 




PLATE XXXVI. 

Eight Paets of the Foue-coated Tube — ^Alimentary Cakal — ^ix one, Showing the Coats 

AND Layers Common to them all. 

Diagram Representing the Stetjctubal Resemblances and Differences of the Eight 
Divisions of the Alimentary Four-coated Tube. 

Examination of it shows that: 1. A connective tissue is common to them all. 2. The 
muscular coat has two layers, except cardiac stomach which has three. 3. The upper 
oesophagus only has striped muscle. 4. The subepithelial coat contains secretory glands in 
two places, viz., oesophagus and duodenum. 5. The muscularis mucosae is continuous. 6. The 
epithelium of oesophagus is stratified pavement. 7. The epithelium of cardiac stomach — com- 
pound tubular glands with short necks, long bodies lined by chief and parietal cells. 8. 
Pyloric stomach — compound tubular glands, long necks, short bodies, chief cells. 9. Duodenum 
— crypts and villi. 10. Small intestine — crypts and villi. 11. Large intestine — crypts. 12. 
Vermiform appendix — lymphoid tissue and incomplete crypts. 

94 



TEE TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT. 95 

Four Coated Tubes, Muscular Motor (see Plate XXXV, mac, 
XXXVI, mic.).— These tubes may be formed from three coated tubes by 
adding to the under side of their epithelial coats one or two very thin 
layers of smooth muscle called the Muscularis Mucosae. The alimen- 
tary canal is the only tube of this class. This is the most complex tube, 
for the reason that it has the greatest number of coats and hence the 
greatest number of functions. The coats are : connective tissue, muscu- 
lar, sub-epithelial and epithelial. As any one or more of these coats 
answers the same purpose in any tube in which it occurs, one description 
will answer for all. It is evident that these coats will have the same 
functions wherever they are found, that is, supporting, contracting, 
uniting and secreting. 

1. Connective Tissue Coat,— This is a thin layer of connective tissue 
which surrounds the tube, for the most part, from the lower end of the 
oesophagus to the rectum. This coat of the oesophagus consists of the 
connective tissue which supports the tube and may or may not be con- 
sidered as a distinct coat. By means of this coat, in any location, a tube 
is supported by attachments to the skeleton or to the other structures 
Eind provided with a blood and lymph circulation. The outside connec- 
tive tissue coats of all tubes having such a coat have the sam^e function 
and hence can be represented by the same model. (See Plate XIII, figs. 
1, 73 and 20.) 

2. Muscular Ooa^.— This is composed of two layers of muscle 
throughout the whole length of the alimentary canal except at the cardiac 
end of the stomach where there are three. In the upper half of the 
oesophagus the muscle is striped, in the lower half smooth. The alimen- 
tary canal is a motor tube because progressive motion of its contents in 
a certain direction is necessary. This can be accomplished only by a 
contractile tissue which must be arranged according to some definite plan. 
In the majority of motor tubes two layers of muscle are sufficient; an 
external longitudinal and an internal circular. In a very few three lay- 
ers are found. Of the two layers the external longitudinal by contrac- 
tion shortens the tube and stiffens it while the internal circular, by waves 
of contraction from above downward, propels the contents towards the 
lower end of the tube. In the cardiac stomach, the internal oblique layer 
of muscle is composed of a few radiating strands over the fundus, the 



96 A CONSTRUCTIVE METHOD IN HISTOLOGY. 

effect of whicli is not apparent. Layers of muscle are joined by thin 
connective tissue which carries small blood vessels, lymphatics and plex- 
uses of nerves. In the pyloric stomach the internal circular layer of 
muscle is thickened to form the sphincter pylori. The character of the 
contents of a tube governs the amount of muscle which it contains. The 
contents of the four coated tube are large. There is no force behind 
them and, therefore, a well developed muscular coat is provided in order 
to move the contents from one end of it to the other. The muscular 
coats of all tubes having more than one layer of muscle have the same 
function because they have the same tissues arranged in the same man- 
ner. This coat then, wherever it occurs, can be represented by general 
models of various thicknesses indicating the layers. (See Plate XIY, 
figs. 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 and 13.) 

3. Suh-Epithelial Coat.— This coat is composed of areolar tissue 
which joins the muscular and epithelial coats and provides them with 
blood vessels, nerves and lymphatics. In two places, the oesophagus and 
duodenum, secreting glands are found. While this coat unites the epi- 
thelial and muscular coats, it allows freedom of motion of the former 
upon the latter on account of its areolar character. It is widest in the 
stomach and here the epithelial coat is more freely movable than else- 
where. It contains solitary glands, agminated glands and secreting 
glands. As it is always composed of the same areolar tissue and has 
practically the same function, it may be represented by models of are- 
olar tissue containing the characteristic structures. (See Plate XIII, 
figs. 14, 15, 16, 17 and 18.) 

4. Epithelial Coat.— This coat is also called mucous membrane or 
mucosa. The term epithelial coat is preferred because it suggests ant/ 
secreting function rather than a mucous secreting function. It is made 
up of three parts : a muscularis mucosae, which is external and composed 
of two very thin layers of smooth muscle— an external longitudinal and 
an internal circular ; a connective tissue base containing in some places 
diffuse masses of lymphoid tissue, in other places solitary glands and 
agminated glands, nerves, blood vessels and lymphatics; lastly, some 
form of epithelium such as stratified pavement in the oesophagus, tubular 
glands in the stomach, crypts of Lieberkiihn with many goblet cells in 
the large intestine, crypts of Lieberkiihn and villi in the small intestines. 



THE TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT. 97 

and incomplete crypts embedded in lymphoid tissue in the vermiform 
appendix. The epithelium of this tube extends from the mouth to the 
anus, a distance of nearly thirty feet in man, and exhibits a variety of 
functions. The muscularis mucosae distinguishes this type of tube from 
all others. It is required for the proper adjustment of the epithelial 
structures to the moving contents and for the purpose of shortening the 
villi of the small intestine. There is, perhaps, no other tube in which the 
adaptive function of the muscularis mucosae would be of any advan- 
tage to the tube because there is no other tube having the same character 
of contents. By its action the delicate epithelial coat is so adjusted to 
the contents that digestion and absorption are favored and a pouched 
condition, which would be the result of a driving force of the strong 
muscular coat upon hard substances within, is avoided. The epithelial 
coat is more or less movable upon the loose areolar sub-epithelial coat 
underneath and peristaltic action would be likely to push it in front of 
solid contents and tear it, but the muscularis mucosae draws it back and 
gives it some rigidity whereby it is protected. This tube then is a motor 
tube adapted to the progressive motion of its contents and also to the 
adaptation of its epithelial coat to the contents. The different layers 
of the muscular structures may be represented by general models. (See 
Plate XX, figs. 1, 5, 6, 14, 76, 73, 25 and case outlines of four coated 
tubes. Also see Plates XV, XVI and XVII.) 

Tissues as Building Materials.— In the construction of tubes (which 
we have seen constitute the structural and functional units of the body) 
the building materials must be used according to the capacities which 
they have. In no case is a superfluous or unnecessary tissue present. 
These building materials or tissues will necessarily be the same in any 
tube of more than one layer on account of requirements which are com- 
mon to all of them. 

1. Each tube must have a framework which gives it form, dimensions 
and resisting capacity and also provides it with a means for the intro- 
duction of a blood, lymph and nerve supply as well as secreting glands. 
In looking over the varieties of tissues it is obvious that a combination 
of fibrous and elastic connective tisues has these capacities and is there- 
fore employed for these purposes. Now, since all tubes, excepting the 
one layer tubes, are composed of more than one variety of tissue, it f ol- 



98 A CONSTRUCTIVE METHOD IN HISTOLOGY. 

lows that connective tissue will be essential to tlie composition of them 
all. Outside coats, sub-epithelial coats, epithelial bases and intermuscu- 
lar layers, which together form the framework, are all composed of this 
tissue and occupy the same relative situations in the walls of tubes. 
This fact facilitates their construction. 

2. All tubes of more complex structure than the one coated, and even 
a few of these, must have some form of motor apparatus because their 
contents must, of necessity, be moved and they cannot be moved without 
a motor power. The motor apparatus is composed of the contractile 
tissues— muscle and ciliated cells. These will vary in distribution ac- 
cording to the work to be done. The ciliated cells are found in the lining 
while muscle forms the surrounding layers and coats. All large tubes 
have such an apparatus and hence their construction is further simplified. 
3. Each tube must have a form of tissue which is capable of rear- 
ranging chemical elements and thereby producing such chemical products 
as secretions, excretions and the complex variety of chemical bodies 
which account for vital phenomena. This most complex form of all cell 
actions is provided by some form of epithelium. There are, perhaps, no 
cells in the body having a greater range of capacity than epithelial cells. 
The life and continuation of the living body are possible only because 
these cells stand between the insoluble foods of its environment and the 
body cells, in the capacity of chemical transformers by the action of 
which chemical compounds are made soluble, dialyzable and reconstruc- 
tive and their chemical elements are qualified to succeed their predeces- 
sors in the important role of protoplasmic constituents. We know, 
therefore, that all tubes will have epithelium. In cross sections of tubes 
the nervous system does not appear to any appreciable degree ; hence we 
see that connective tissue, muscle and epithelium are the three visible 
tissues which will enter into the formation of tubes in proportion to their 
requirements. The plan according to which they are arranged will nat- 
urally be the same in all, that is, muscle and epithelium enclosed in a 
framework of connective tissue or resting upon it as a foundation. Prac- 
tically, then, in tube formations we are dealing with three tissues as far 
as the microscope is concerned— connective tissue, muscle and epithelium. 
This may be understood from the following outline : 



TUr. TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT. 



99 



OUTLINE OF THE THREE TISSUES SEEN IN TUBE STRUCTURES. 


One Layer Tube. Non-motor. 


Okgans. 


Epithelium. 


Muscle. 


Connective Tissue. 


Capillaries. 


Simple pavement. 






One Coated Tubes. Non-motor. 


Organs. 


Epithelium. 


Muscle. 


Connective Tissue. 


Tubuli uriniferi. 
Tubuli seminiferi. 
Crypts of Lieberkiihn. 
Serous membranes. 
Graafian follicle. 
Very small ducts. 
Acini of secreting glands. 
Vestibule, utricuius. 
Sacculus of ear. 
Semi-circular canals. 

Cochlea. 

Olfactory nasal mucosa. 

Skin. 

Hair follicle. 

Lacrimal sac. > 

Nasal duct. 


Simple rodded, cubical. 

Stratified embryonic. 

Simple columnar. 

Simple pavement. 

Stratified embryonic. 

Simple cubical. 

Simple polygonal. 

Simple cubical, hair cells. 

Sustentacular cells. 

Simple cubical, hair cells, sus- 
tentacular cells. 

Endothelium, pillar cells, sus- 
tentacular cells. 

Olfactory cells and sustentacu- 
lar cells. 

Stratified pavement. 

Stratified pavement. 
Simple pseudo-stratified col- 
umnar. 
Stratified pavement. 




Basement membrane. 
Basement membrane. 
Basement membrane. 
Fibrous tissue in layers. 
Connective tissue. 
Basement membrane. 
Basement membrane. 

Dense connective tissue. 
Connective tissue. 

Connective tissue. 

Connective tissue. 

Connective tissue with 

glands. 
Connective tissue. 
Connective tissue with 

glands. 
Connective tissue with 

glands. 


One Coated Tube. Ciliary-motor. 


Organs. 


Epithelium. 


Muscle. 


Connective Tissue. 


Nasal duct. 
Tympanum of ear. 
Eustachian tube. 
Respiratory nasal mucosa. 


Stratified ciliated. 

Simple pseudo-stratified cili- 
ated. 

Simple pseudo-stratified cili- 
ated and stratified ciliated. 

Stratified ciliated. 




Connective tissue with 

glands. 
Connective tissue. 

Connective tissue. 

Connective tissue. 


Two Coated Tubes. Ciliary-motor. 


Organs. 


Epithelium. 


Muscle. 


Connective Tissue. 


Trachea and large bronchi. 


Stratified ciliated. 




Connective tissue with 
C-shaped rings of hya- 
line cartilage and secret- 
ing glands. 



100 



A COySTRUCTIYE METHOD 7X HISTOLOGY. 



OUTLINE OF THE THEEE TISSUES SEEN IN TUBE STEUCTUEES— Cow/enMeti. 



Three Coated Tubes. Musculak-motor. 



Organs. 



Vagina. 
Upper ureter. 
Lower ureter. 
Urinary bladder. 
Gall bladder. 
Small artery. 
Small vein. 
Large duct. 
Seminal vesicles. 

Corpus spongiosum. 
Vas deferens. 



EPITHEXICir. 



Stratified pavement. 
Stratified transitional. 
Stratified transitionaL 
Stratified transitional. 
Simple columnar. 
Simple pavement. 
Simple pavement. 
Simple columnar. 
Simple pseudo-stratilied colum- 
nar. 
Stratified columnar. 
Stratified columnar. 



MCSCLE. 



Co>XECTivE Tissue. 



Two layers, smooth. 
Two layers, smooth- 
Three layers, smooth. 
Three layers, smooth. 
Two layers, smooth. 
One layer, smooth. 
One layer, smooth. 
Two layers, smooth. 
Two layers, smooth. 

One layer, smooth- 
Three layers, smooth. 



Connective 
Connective 
Connective 
Connective 
Connective 
Connective 
Connective 
Connective 
Connective 



tissue, 
tissue. 

tissue, 
tissue, 
tissue, 
tissue, 
tissue, 
tissue, 
tissue. 



Connective tissue. 
Connective tissue. 



Three Coateb Tubes. Musculak-ciliaey Motor. 



Orga:ss. 



jcpixheliu:m. 



Muscle. 



CoN>-ECTrvE Tissue. 



Fallopian tubes. , Simple ciliated. 

Uterus. Simple ciliated. 

Epididymis. Stratified ciliated. 

Medium and small bronchi. Stratified ciliated. 



Vas deferens. 



Stratified ciliated. 



Two layers, smooth. 
Three layers, smooth. 
Two layers, smooth. 
One layer, smooth. 

Three layers, smooth. 



Connective tissue. 
Connective tissue. 
Connective tissue. 
Connective tissue, glands, 

cartilage. 
Connective tissue. 



Four Coated Tubes. Musculae-motob. 



Orgaxs. 



Upper oesophagus. 

Lower oesophagus. 
Cardiac stomach. 
Pyloric stomach. 
Duodenum. 
Jejunum. Ileum. 
Large intestine. 
Vermiform appendix. 



Epithelium. 



Stratified pavement. 

Stratified pavement. 
Simple columnar. 
Simple columnar. 
Simple columnar. 
Simple columnar. 
Simple columnar. 
Simple columnar. 



Muscle in Muscular 
Coat. 



Two layers, stratified 

voluntary. 
Two layers, smooth. 
Three layers, smooth. 
Two layers, smooth. 
Two layers, smooth. 
Two layers, smooth. 
Two layers, smooth. 
Two layers, smooth. 



Muscle rx Epithelial 
Coat. 



One layer, smooth. 

One layer, smooth. 
Two layers, smooth. 
Two layers, smooth. 
Two layers, smooth. 
Two layers, smooth. 
Two layers, smooth- 
One incomplete layer. 



co>'sective 
Tissue. 

Connective tissue. 



Connective 
Connective 
Connective 
Connective 
Connective 
Connective 
Connective 



tissue, 
tissue, 
tissue, 
tissue, 
tissue, 
tissue, 
tissue. 



THE TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT. 



101 



THE FIVE CIRCULATIONS. 



1. Systemic. 
See Plate ■{ Aorta. 
XXXVIa. 



2. Pulmon- 
ary. 
See Plate 
XXXVII. 



1, Blood. - 



3. Portal. 

See Plate 

XXXVIII. 



Arteries. 

Capillaries. 

Veins. 



Venae Cavae. 



Right auricle. 
Right ventricle. 
. Pulmonary artery. 
Pulmonary veins. 
Left auricle. 
Left ventricle. 



Aorta. 



Respiratory. 



Right ventricle. 
Pulmonary artery. 
J Pulmonary capillaries. 
Pulmonary veins. 
Left auricle. 
Left ventricle. 



NUTRITIVK. 



Bronchial artery. 



Bronchial veins. 
Pulmonary veins. 



Veins which Form 
THE Portal. 



Functional. 



1. Gastric. 

2. Splenic. 

^•S.Ef''''*'' ^««^^-^' Portal. 



teric 
4. Inferior 
teric. 



mes en- 



1. Interlobular veins, 

2. Capillaries. 

3. Interlobular veins. 

4. Sublobular veins. 

5. Hepatic veins. 

6. Inferior vena cava. 



Nutritive. 



Hepatic 
artery. 



Hepatic 

veins. 



Functional. 



4. Renal. 
See Plate ■! 
XXXIX. 



Long. 



1. Incomplete arch. 

2. Interlobular artery. 

3. Vasa aJBPerentia. 

4. Malpighian tuft. 

5. Vasa efferentia. 

6. Venous plexus. 

7. Interlobular vein. 

8. Venous arch. 

9. Renal vein. 

10. Inferior vena cava. 



Pressure Reducing. 



Short. 



1. Renal artery. 

2. Incomplete arch. 

3. Arteria recta. 

4. Capillaries. 

5. Venae rectse. 

6. Venous arch. 

7. Renal vein. 

8. Inferior vena cava. 



Sources. 



1. Lymph spaces. 

2. Perivascular spaces. 



2-Ly°^P^-i 3: Serous cavities. 



! 4. Lacteals. 



Medium Vessels. 



1. Lymph capillaries. 

2. Lymph vessels. 



Large Trunks. 



Exits. 



Thoracic duct. 

Right lymphatic trunk. 



-{ Left subclavian vein. 
I 
-{ Right subclavian vein. 



102 



A OOlKSTBUCTUE METHOD IN HISTOLOGY. 



im^iFi 



[C EYSTT.M: 



^'TTTSIOKS, 



JXESCEXPTLOK. 



lEr^MTSATIOK. 



AJTD Steitctuee:. 




1. iympi 
spaces. 




r1 



1. Xiympb 



m^ mostly 
-vatveA fiilUrw- 
ing -£be general .^ 
comse of tihf- 
^eiiis towKrd 
"Bos itsBXt. 



1. TboTaeic 
duct 



2. Ei^t Ijn^ili^ 



jngD- 

at its 

vith 



3. Jk. ^«tem of 

tfte 



S. Tjiwtowan 



■i. lilhfit i, CAA- 



mtieonlbirjiaies 



4. S«iro«s 
iWiBiiiiiginiBR 



2. Ii3riiipll 



sever itniaiBa. 
and tfpr small 
Tocn L or aval 
bocies sitnaxed 
on uit lympii^ 
■V e E f ^ 1 s and 
Ttez:: iheir la&- 



L QuOffiK. 







Fibrons ti^me ■wifh 
1. CiqwnTs. -< ^aootia mnsde in 
I Aehneriiode&. 



2. Tzabecn- 



"FJrtegwtMiti cf the 
aqsnle witfaxn the 
aooea. 



S. Cortex. -^ Onterzone. 



-i. Cardeal 



CompamiwartB of 
ite cortex 1)^ ex- 
tawnrntw ef'the 
taiteeiQe. 



a. "M^WtnTlH ., ^ Central part 

_ -w « a — 1 I CoHHaianments o f 
\ -»eflBl-j fliemediillabTthe 



nhaamm. ] j^-a.] 
& ASereBtj I^roiA^weaEdBlead- 



^igtei 
agriiwiliiifwilrff. 



9. mUc Mt ! Ij^ank^vanAleBi- 

1 a - - - 



Right Int. jugular vein 
Eight com. carotid artery 

Right sub-clavian vein 
Sup. vena cava 

Pulmonary artery 

Heart 

Thoracic duct 
Hepatic vein 

Liver 

Hepatic artery 

Gastric vein 

Portal vein 

Renal vein 

Renal artery 

Kidney 

Inf. vena cava 

Large intestine 



Small intestine 



Small vein 
1-11-35 




Left int. jugular 
Left com. carotid 
Left subclavian artery 

Arch of aorta 
Pulmonary veins 

Lung 

(Esophagus 

Stomach 
Spleen 
Splenic artery 

Splenic vein 
Sup. mesen.^vein 
Aorta 

Mesenteric artery 
Mesenteric vein inf. 

Lymph vessels 
Mesenteric gland 



°" Capillary 40 



Small artery 1-11-35 



PLATE XXXVlA. 



103 




h)ronchiai Artery 



VuLrnonaYy V?in. 
Bronchial vein. 



PLATE XXXVII. 



104 




iTiiiLokilnr \/ein 



Liver 






\irctirLoluLaY Vein' 



i^ \/iln.77. 



tfuct 



PLATE XXXVIII. 
DiAGExVM OF Four Li\^r Lobules Showing Circulation. 



105 



PLATE XXXIX. 

Diagram Showing the Circulation from Aorta to Inferior Vena Cava Through Kidney. 
Divisions of a kidney tube, microscopic section of kidney, pelvis, ureter and bladder. 

Drawing is extremely schematic. 
106 













.o|.ejnnf of i(>««ttif 

Jfick of iUciciiXt. 



TEE TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT, 



107 



LOCATION OF TISSUES IN TUBULAR ORGANS. 



Epithelium. 



Simple. 



Pavement. 



Entire vascular 
and lymphatic 
systems, serous 
membra nes, 
alveoli of 
lungs, capsules 
o f Bowman, 
scala vestibuli, 
scala tympani 
of cochlea. 



Ciliated. 



Uterus, Fallo- 
pian tube. 



Columnar. 



Alimentary 
canal, ducts. 



Cubical. 



Necks, loops of 
H e n 1 e and 
straight por- 
tions of tubuli 
uriniferi, small 
ducts, s e m i - 
circular canals, 
utriculus, sac- 
culus of inter- 
nal ear. 



Polygonal 
Polyhedral. 



Acini of secreting 
and excreting 
glands. 



Simple Pseudo-stratified. 



Columnar. 



Lacrimal sac. 



Ciliated. 



Tympanum of 
ear, eustachian 
tube, respira- 
tory nasal mu- 
cosa. 



Stratified. 



Pavement. 



Epidermis, mouth, 
oesophagus, vagina, 
cornea, entrances to 
body, nasal duct. 



Columnar. 



Urethra, vas deferens. 



Ciliated. 



Transitional. 



Eustachian tube, tra- Pelvis of kidney, 
chea, large bronchi, ureters, bladder, 
medium, small bron- 
chi, epididymis, vas 
deferens, nasal duct. 



Neuro-epithelium. 



Retina, cochlea, olfac- 
tory nasal mucosa. 



Muscle. 



Striped 
Voluntary. 



Two layers in the 
upper half of the 
oesophagus. 



Smooth. 



One, two or three 
layers in the walls 
of muscular and 
muscular ciliary 
tubes and in the 
lower part of the 
epithelial coats of 
four coated tubes. 



Connective Tissue. 



Connective 
Tissue. 



Outside coats of 
tubes, serous mem- 
branes, basement 
membranes. 



Areolar. 



Sub-epi t h e 1 i a 1 
coats and epithe- 
lial bases of tubes. 



Lymphoid. 



Solitary glands, 
Peyer's patches, 
diffuse masses in 
bases of epithelial 
coats. 



Cartilage. 



Outside coats of 
trachea, large 
and medium 
bronchi. 



108 



A CONSTRUCTIVE METHOD IN HISTOLOGY. 



FUNCTIONS OF TISSUES. i 

1 


Tissues. 


Simple. 


- 1 
Stratified. 


Pavement. 


Ciliated. 


Polygonal. 

POLYHEliRAL. 


Columnar. 


Pavement. 


Ciliated. 


Columnar. 


Transi- 
tional. 


Epithelium. ^ 
Connective. ■ 

Muscle. 
Nerve. 


Osmosis, 
Secretion. 


Motor. 


Secretion. 
Excretion. 
Chemical 
transformers. 


Secretion. 
Absorption. 
Chemical 
transformers. 


Protection. 


Motor. 


Secretion. 
Protection. 


Secretion. 
Protection. 
Non-absorp- 
tion. 


White 
Fibrous. 


Yellow 
Elastic. 


Areolar. 


Adipose. 


Lymphoid. 


Cartilage. 


Bone. 


Neuroglia. 


Support. 
Eepair. 


Passive 
motion. 


.Support. 
Eepair. 


Protection. 
Fund of po- 

te n t i a 1 

energy. 


Phagocytosis. 
Eepair. 


Stiffening, 
Protection. 


Support. 
Eed blood 
manufactory. 


Support of 
nerve cells. 

1 


Striped 
Voluntary. 


Striped 
Involun- 
tary. 


Unstriped 
Involun- 
tary. 


i 
1 


Motor, ther- 
mogenic. 


Motor, ther- 
mogenic. 


Motor, ther- 
mogenic. 


Cells. 


Fibers. 




Energy gen- 
erators. 


Energy trans- 
mitters. 












1 



Contents of Tubes Govern Their Motor Structures.— It is evident 
from the nature of the case that all tubes of any considerable diameter 
must be provided with some form of apparatus for the purpose of setting 
in motion their contents. This apparatus is composed of the contractile 
tissues— muscle or ciliated epithelium. Muscle is used where consider- 
able force is necessary and cilia where little is required. Both forms are 
present when the degree of force required is subject to marked varia- 
tions. The amount of motor power required in any given case depends 
upon the character and condition of the contents. With the exception 
of the two coated tubes all large tubes have muscular coats. As their 
contents vary, sometimes being large, liquid or solid, and sometimes 
small liquid and gaseous, some of them have also ciliated linings. Cilia 
provide a constant, gradual, progressive motion and muscles a rapid, 
strong, intermittent motion. An examination of the large tubes of the 
body shows this to be the case. The four coated tube or alimentary canal 
must of necessity be a muscular-motor tube and in all the larger animals 
could not reasonably be ciliated. The contents are large, liquid and solid 
and must be kept in motion to serve the purposes of digestion, absorption 



TEE TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT. 109 

and expulsion. Cilia, if present, are soon worn off by contact with solid 
matter and furthermore are ineffectual as a motor power. Hence this 
class of tube is muscular-motor and not ciliary-motor. The character 
of the contents requires well-developed muscular layers and coats for the 
large amount of work accomplished by them must be done at short inter- 
vals and for long periods of time. Probably the best types of muscular- 
motor tubes have three layers of muscle— external longitudinal, middle 
circular and internal longitudinal— but in most cases only two are pres- 
ent. The variety of muscle is almost always smooth. The alimentary 
canal has two well-developed layers forming its muscular coat, the com- 
bined action of which is certain in its results. In addition to the muscle 
of the muscular coat one or two well-developed layers are found in the 
outer portion of the epithelial coat and are called the ^^muscularis 
mucosae." The adaptation of the epithelium of the lining makes it a 
necessity. 

Among the three coated tubes the Fallopian tubes, uterus, epididymis, 
first part of the vas deferens, portions of the vasa efferentia of the tes- 
ticle, medium and small bronchi have both muscular coats and cilia. 
Here the character of the contents varies according to circumstances. 
In the generative tubes of the female during labor the contents are solid 
and large and the expulsive force required is great. Hence a well- 
developed, high type, three layer muscular coat is present. Especially 
is this true of the uterus. At other times the contents are small and 
liquid and cilia are adequate excepting, perhaps, during the aspirating 
effect displayed at the time of sexual orgasm. The Fallopian tubes are 
arms of the uterus and have a motor structure less strongly developed. 
They have two layers of muscle and a ciliary lining. The muscular 
requirements are never great and therefore the muscles are poorly devel- 
oped. The contents are small and liquid and cilia are sufficient except- 
ing, perhaps, during sexual excitement. The vagina has two rather 
poorly developed layers of muscle ; for its motor requirements are few. 
The epididymis has two muscular layers and a ciliary lining. The mus- 
cle is fairly well developed. The contents are small and liquid. Muscle 
is required when the products of the testicle are ejected. At other times 
cilia are sufficient. The vasa efferentia of the testicle are the first por- 
tions of the tubes leading from the testicle to show a motor apparatus 



110 A CONSTRUCTIVE METHOD IN HISTOLOGY. 

wMch is therefore poorly developed. The vas deferens has three well- 
developed layers of muscle and only a small part ciliary. The contents 
are small and liquid. The distance from the testicle to the urethral 
meatus is considerable and somewhat circuitous and a sudden ejection 
of the seminal fluid is necessary for fertilizing purposes. Hence a 
strong muscle is required at such times. 

The bronchi within the lungs— medium and small— have both muscle 
and cilia. The contents are small liquid and large gaseous. It is quite 
certain that changes in the diameters of these tubes are necessary to reg- 
ulate the quantity of air passing through them in respiration. A mus- 
cular coat is required for this purpose. Only one layer of circular 
muscle is present ; the shortening and stiffening effect produced by the 
longitudinal layers not being needed. In ordinary times cilia are suffi- 
cient for the removal of the small liquid contents and foreign matters 
which are drawn into them by inspiration. In the vascular system only 
the small arteries on the proximal side of the capillaries have a distinct 
muscular coat well developed. The contents are large and liquid and the 
muscle is circular. Here a peripheral resistance is necessary to govern 
the variations in blood pressure. A cut-off action is all that is needed 
and hence the muscle is limited to small lengths of tubes. In these tubes 
the propelling force originates in the heart and the motor character of 
the small arteries governs the blood pressure and rate of flow. Here the 
requirements are unlike those of any other tubes since the muscular coats 
are not the direct cause of the motion of their contents. Evidently cilia 
would be of no use here. In the large vessels alternating layers of 
smooth muscle and elastic tissue give to those tubes a gradual recoil 
resulting in the production of a continuous stream. 

The upper parts of the ureters have two layers of muscle while the 
lower parts have three. This difference in structure is due to a differ- 
ence in function. The contents are liquid and must be forced into the 
bladder under considerable pressure. The lower parts of the ureters 
are injectors and force urine into the bladder in spurts. A high type of 
motor apparatus is required here while it is not needed in the upper 
parts. Cilia could accomplish nothing in these tubes. In none of the 
three coated tubes would a muscularis mucosae be of any use as the local 
adaptation of their epithelial linings to the contents is not essential. 



THE TUBE A8 A STRUCTURAL AND FUNCTIONAL UNIT. Ill 

The two coated tubes (traeliea and large bronchi) are ciliary-motor. 
The contents are small liquid and large gaseous, and cilia constantly 
waving toward the upper end of those tubes are sufficient in ordinary 
circumstances. Since they have ^ X ' ' shaped rings of hyaline cartilage 
throughout their whole length a muscular coat would be of little use. 

Of the one coated tubes, the nasal duct, tympanum of the ear. Eus- 
tachian tube and respiratory nasal mucosae are ciliary motor. Here the 
contents are small liquid and gaseous, and muscle is unnecessary. The 
cilia are sufficient for all motor purposes. All of the remaining one 
coated and one layer tubes are non-motor. 

Organs Which Apparently Do Not Conform to the Tube Plan 

OF Structure. 

There still remain certain parts of the body which apparently, at 
least, do not conform to the tube plan of structure. These parts are the 
nervous system, thymus, spleen, lymph nodes, and adrenals. 

'*In the development of the cerebro- spinal system the rudimentary 
part is formed from the thickened medullary parts of the involuted epi- 
blast, the ridges of which rising from the surface of the epiblast, are 
united dorsally along the middle line so as to form a hollow medullary 
tube. This tube is wider at its anterior or cephalic extremity and this 
dilated portion is divided by partial constrictions into three primary 
cerebral vesicles which represent the anterior, middle, and posterior 
divisions of the brain. The spinal portion retains a more uniform cylin- 
drical shape. The continuous cavity enclosed within the primitive 
medullary tube is the same with that which constitutes the central ven- 
tricles of the brain and central canal of the spinal cord.'' (Quain's 
Anatomy.) Thus the brain during its early existence is the dilated ante- 
rior portion of the primary medullated tube derived from an indentation 
of the epiblast and the spinal cord is the remainder of that tube. In the 
adult the central ventricles of the brain and canal of the spinal cord still 
remain, showing that a tube plan is the plan of formation, although many 
structural additions and modifications have been made. The ventricles 
and central canal are lined with simple ciliated epithelium (fifth ventricle 
lined with simple pavement). Structurally then the brain and cord are 
covered on the outside by a connective tissue layer {pia mater) and are 



112 



A COW^TRUCfTIWE METHOD IS HimOlO&F. 



irEBVOCB JsV'S TfKW 



'iO^BaS. 



ILOems- 



rxr^TC-TCj 



T >iKM< 'K-l Tf" f't-Tiy. 



^ Jim* Ttr:;: 



-elH.- 



ffluuytifln- 






] 









Bypertrc; 



S-PSa 






■5 i r.^ 

. tv::£. 






ilScr- 



LCMdoi 



] 



1 



fllBlAMQpCC 



fifth liSPtsr. 



eeii&. 



1 £ yer-- t 




JtfM fllMllll to 



lispnielialtoi 



mens iffaikfi amitejl 



TEE TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT. 



113 



NERVOUS SYSTEM,~Conti7Uied. 



Organ. 



Division. 



1. Hippo- 
campus 
major or 

cornu 
ammonis. 



Cerebrum 
continued. ■{ 



2. Special 

masses of 

gray 

matter. 



Division. 



1. Internal 
white zone. 
2. Middle 
gray zone. 
3. External 
white zone. 



Subdivision. 



Description. 



Alveus. ^ 

Stratum oriens. ■} 



. Stratum cellularum pyra- J 
midalium. l 



Stratum radiatum. -l 

Stratum lacunosum. •{ 
Stratum moleculare. -I 



Ventricular s u r - 
face. 

Fourth cortical 
layer. 

Third cortical^ 
layer. 

Branches of thirds 



Structure. 



Medullated nerve 
fibers. 

1. Spindle nerve cells. 

2. Nerve fibers. 

Large pyramidal nerve 
cells whose branches 
extend into the 
alveus. 

Branches of the pyram- 
idal cells. 



layer. i 

Parallel to alveus. ■{ Axis cylinders 



Lamina medullarisj 
involuta. 



Vertical and lateral J 
cell branches. i 

Outer cortical! 



Small pyramidal gang- 
lion cells. 



4. Fascia J 1. 
dentata. \ 2. 



Nerve fibers. 
Ganglion cells. 



layer. 



Thickened edge of 
cortical layer of 
the cerebrum. 



1. Within 
the white -i 
matter. 



1. Corpus 
striatum. 



2. Optic 
thalamus. 



1. Nucleus J lutravent r i c u 1 a r 
caudatus. i portion. 



\n£"'jE.trsTentrlcul.r. 



laris. 1 P°""">- 



1. Inner I Two unequal divi- 
nucleus. J sions of gray mat- 

2. Outer | ter by white sep-" 
nucleus. I tum. 



3. Corpus sub- J 1, Cells, J Brown stratum of J 
thalmicum. | 2. Fibers, i gray matter. | 



4. Corpora 
quadri- 
gemina. 



1 Antprior I ^^^^ bodies on the 
2. Posterior. ^^^ sylvian duct. 



Nerve fibers. 

Medullated fibers. 

1. Pyramidal cells. 

2. Polymorphous cells. 

3. Fusiform cells. 

1. Large, multipolar 
nerve cells. 

2. Small, ganglion cells 

3. Nerve fibers. 

1. Multipolar nerve 
cells. 

2. Medullated nerve 
fibers. 

1. Multipolar nerve 
cells. 

2. Medullated fibers. 

3. Ganglion cells alter- 
nating with medul- 
lated fibers. 

Multipolar cells. 

Fine medullated fibers. 

1. Various shaped nerve 
cells. 

2. Medullated fibers. 

3. S m a 1 1 , multipolar 
cells. 

4. Large, multipolar 
cells. 



2. Along 
the floor of 
third ven- 
tricle. 



1. Lamina cinereum. 



2. Tuber cinereum. 



3. Infundibulum. 



Between chiasm 
and the corpus 
callosum. 

Part of the floor of 
the third ven- 
tricle. 

Hollow conical 
process of the 
tuber cinereum. 



4. Corpora albicantia of pos- J Two gray nuclei 
terior perforated space | within whitefibers. 



1. Ganglion nerve cells 

2. Special bundles of 
nerve fibers. 



lU 



A COySTBUCTIYE METHOD FS' HISTOLOGY. 



IfEBTOrS SY^TESL—CamHrnmed. 



OasA^rs. 



DwaMSiRio: 



Dinsio^rs. 



? UBDIVISIO^fS. 



DsaCBIFTIOiN. 



STBrCTCSE. 



%. Craaa 



1. Ventral part 
or cru5ta pe- 
duncoli. 



1. Ascending nerTe 

fibeii 



2. Beseaiding nerre. 



Fibers an their way ! 

niMwle mad eei!d>ral'^ 
eoites. [ 



Two^ tkiek 

jjiuaAa of HBT- 

foas Bftstter 
mMitimg lAe 



WAile pni 



spkeres 

Oepn 

lii. 



or 

nigra. 



firo^tte CERbcaleaep- 

capsules intexjtupled 
by f^tie thalamiia. 



A daik tract of gxay 

matter dnaiBiabiiig as 

A fmpmtmlt^ aics !)€-] it advaGMBes tn^ the 

itia/ tvees tiie craata and."( pons and fimang a- 

I tegmeBtmn. j thickened, edge aear 

the ocaloHBOtor 

I groove. 



[ Transveise, longitadi- ] 

■-j nal nerre fiheis en--^ 

I dosing nerre crila. [ 



3L Doaaal pmrt 



LEstGHiaK of 
tip retiflarK 



tMn layer of gziy 



2. Gray matter contra- | A 
ned from the pons^ 
andmfKJnTTa. I Beaialtn]i& 



'SJ^ 



S, Bodei of the oculo- 
motor and patfa£ti< 

nerrea. 



^ 



3L Fobs 
Taroliiai 
titeriB 



A bri dge of 
vUfce aan gny 
Battcrirkose 

tramsTerse 
fihoB ante the 
tw katvcs of 

■kuMe l^rc'l" 
dimal fibers 
Urn an- 

P J r *-' 

OlfvUTT 

kodtf' of tke 
MoAdla. tke 
lateral and 
pBtofae 




1. Dosaalpait. 



L Continaation of the^ 
formatio reticolaria. 



2. day natter from the] 
^ mBduTla. I 

3L Nuclei of the tzl- 
&eial, abdueei 



Groups oi iKTve cdb] 
along tte loor of theH 
syHJiH aqaednct. I 

Tnaaiene. kn^itiuli- 
nal nerve fibezs en-. 

dosing groups of 
nerve certa. 

Areas scattered throu^b-J 
oat the reticnlTiTTi. ] 



1. ox ins iTt- 1 
[, abdueeaa^J 



A nhfft of grav- matter I 
fiOB Sbe k>«^ half of^ 
fte matti ealar flooc I 



2. V«tTal jacwt. 



X Ftatalomg 

fte fimi'lkifja > 
tride. 



1. Fibers uniting the 
two katies of the 

2. Flbas of anterior k 
pji a m d a on tkeir 
way tofte eewiii— >. 

S. K«r«e dSa betweea 



wcJUK ^"ifc^fii endasi^g j 
aerve eeDs aad le-'j 
aewMing ftc fionaatio 

f»jtl ^l1«TT^. I 



1. l^lHtaBtia ferrugl- 

nea. 



1 



A layer of edis ao 
molted as to be 
lUe to the naked eye, 



i?rj 

Tiai-J 

ye. 1 



2. FOaterior longitudi- J 
nal bundles. I 



A continnation of the J 
fibers from the an— | 
terior ground bandies. | 



MeduHated 
nerve fibers. 



Medtillated 
nerve fibers. 



Multipolar 
nerve cells. 
Granular 
ground sub- 
stance. 



MeduILated 

fibers. 
MuUipc^ar 
nerve eeUSk 



Multipolar 
nerve cells. 



MuMpolar 
nerve edla. 

MednQated 
fibers. 

iCultipoIar 
nerve ceils. 

MultipcJar 
nerve cdl& 



Moiupolar 



MeAdlated 
fibeisand 
BBltipOiar 



LaigeaBulti- 
polar nerve 
cdls deeply 

pigmented. 

MednHatfd 

nerre fihraa. 



THE TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT, 



115 



NERVOUS SYSTEM..— Continued. 



Organ. 



5. Medulla 
oblongata. 



White Matter. 



1. Anterior 
mid. 



py ra- 



Description. 



1. Continuation of the direct 
pyramidal tract of the anterior 
columns of the cord which does 
not take part in the decussation 
of the pyramids. 

2. Continuation of the crossed 
pyramidal tract of the lateral 
columns of the cord. 



2. Lateral tract. 



3. Eestiform body. 



All the fibers of the lateral 
columns except the crossed . 
pyramidal and direct cerebellar^ 
tracts. 



1. Upward continua- 
tion of the poste- 
rior lateral columns 
or columns of Bur- 
dach as arcuate 
fibers. 



1. Fibers 

from the 

cord. 



2. Direct 
tract. 



cerebellar 



3. Fibers from col- 
umns of Goll as 
arcuate fibers. 



Fibers I Cerebellar fibers to 
medulla. | vary body. 



4. Posterior pyra-J ^P^^aj-d continuation of the pos 
T»^?/q 1 tenor median columns or col- 

^^^- ' umns of Goll. 



Termination. 



1. Majority of the fibers 
pass through the pons 
varolii to the cere- 
brum. 

2. Some fibers pass be- 
neath the olivary body 
joining fibers from 
and aid in the forma- 
tion of the fillet. 

3. A few fibers are 
turned to the resti- 
form body and pass to 
the cerebellum. 

These lateral fibers pass 
over the anterior 
pyramid and olivary 
body and arcuate 
fibers to form a part 
of the formatio reticu- 
laris. 



Fibers pass to the two 
hemispheres of the 
cerebellum. 



Becomes the nucleus 
gracilis. 



Structure. 



Medullated and 

non-meduUated 

fibers. 



116 



A CONSTRUCTIVE METHOD IN HISTOLOGY. 



NERVOUS SYSTEM.— Continued. 



Organ. 



Medulla 
oblongata ■ 
continued, 



Additions Which 
Make the Medulla. 



1. Increase in the size 
of the posterior col- 



Desckiption op the 
Additions. 



Description. 



Structure. 



1. Nerve fibers. 



A gradual addition to 
the funiculus gracilis I 
■{ and funiculus cunea-^ MeduUated nerve fibers. 
tus from below up- I 
ward. 



umns of the spinan « r. mnttpr p-x-tpndpfl I 

cord. ^- Jf^^ .?l^"!. „ !?^„ °,- ! - 1 1. Nucleus gracilis. 



Wthe posterior^-— —^—-, 



I 1. Multipolar nerve cells. 

i 2. Nc 



Neuroglia. 



2. Expansion of the 
central canal of the< 
spinal cord. 



3. Decussation of the 
fibers of the lateral J 
columns of the spinal 
cord. 



Separation of the p o s- 
terior horns until they 
are nearly horizontal, 
while the base of the-^ 
anterior horns comes to 
the surface of the floor 
of the fourth ventricle. 

The crossed pyramidal 
tract in decussating cuts 
off the anterior horns, 
and the several parts 
become the lateral nu- 
cleus. 



Funiculus teres. 



J 1, NcHroglia. 
1 2. Multipolar nerve cells. 



The lateral and longitu- 
dinal fibers of the 
lateral nucleus become-=( 
the formatio reticu- 
laris. 



1. Coarse network of 
gray matter contain- 
ing multipolar nerve 
cells. 

2. Neuroglia. 



4. New gray matte 



1. Accumulation in the 
posterior horns as 
funiculus of Rolando<; 
and tubercle of Eo 
lando. 

2. Nucleus gracilis. 

3. Nucleus cuneatus. 



1. Neuroglia. 

2. Multipolar nerve cells. 



The funiculus of Eo- ] 

lando expands into j 

I the tubercle of Eo- i 

lando. I 

I New additions to the I 
J posterior horns cov- J 1. Neuroglia. 
'^ ered by a thin sheet] 2. Multipolar nerve cells, 
of white matter. | 



4. Dorsal, accessory oli- 
vary body. 

5. Mesial, accessory oli-* 
vary body. 



6. Olivary bodies. 



7. Common nucleus. 



Two small areas near! 1. Neuroglia, 
the olivary bodies. ] 2. Multipolar nerve cells. 



Olive-shaped bodies at j j j^^^^^^^^ti ^^^.^^ g^^^g 

the apparent ends oi-< « " 

the lateral columns, 



f.) 1. External nerve fibers, 
i 2. Multipolar nerve cells. 



Nuclei of the lower six J 1. Neuroglia, 
cranial nerves. ] 2. Multipolar nerve cells. 



THE TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT. 



117 



NERVOUS SYSTEM.,— Continued. 



Organ. 



Divisions. 



1. The two 
hemi- 
spheres. 



4. Cerebel- 
lum. 



Divisions. 



1. Cortical 
gray ^ 
matter. 



Structure, 



1. Molecular 
Layer. 



2. Cells of 
Piirkinje. 



Description. 



2. Vermi- 
form 
process 
uniting the " 
two hemi- 
spheres. 



2. Central 
white 
matter. 



1. Gray 
matter. 



2. White 
matter. 



3. Granule 
Layer. 



4. Nerve 
Fibers. 



Central 
Nuclei. 



Cerebellar 
peduncles. 



1. Branches of the cells of Purkinje. 

2. Small, multipolar cells whose branches extend toward the 
periphery. 

3. Large, multipolar cells whose axis cylinders envelope cells 
of Purkinje (basket). 

4. Neuroglia. 

1. Large, pear shaped nerve cells with antler branches and 
axis cylinders. They are situated between the molecular 
and granule layers, their axis cylinders extend into central 
white matter as medullated fibers, their other branches 
form a dense network in the molecular layer. 

I 1. Small, cells — mostly nuclei — which 
stain deeply whose branches ramify 
among the granule cells, whose axis 
cylinders extend into the molecular 
layer and end in t branches. 
Neuroglia. 

Large multipolar cells whose many 
branches extend into the molecular 
layer, whose axis cylinders extend 
toward the medulla as a dense net- 
work. 
Neuroglia. 

A central mass of medullated nerves forming a centrifugal and 
centripetal path for impulses from and to the nerve cells. 



1. Small ganglion 
cells. 



2. Large ganglion 
cells. 



1. Nucleus dentatus. 



2. Nuclei of the floor. 

1. Processus cerebelli 
quadrigemina. 

2. Pedunouli pontis. 

3. Corpus restiforme. 



Loosely packed pigmented nerve 
cells whose branches extend out- 
ward and whose axis cylinders 
are directed toward the medulla. 

Large, pigmented multipolar gang- 
lion cells and many nerve fibers. 



ad corpora 



1. Medullated nerve 

fibers. 

2. Non-medullated 

nerve fibers. 



118 



A CONSTRUCTIVE METHOD IN HISTOLOGY. 



NERVOUS SYSTEM.— Continued. 



Organ. Divisions. 



6. Spinal 
cord. • 



1. Mem- 
branes. 



Subdivisions. 



1. Dura mater. 



2, Arachnoid. 



Description. 



An external, dense membrane separated from the walls of the 
bony canal by a space containing areolar tissue, fat and exten- 
sive plexuses of veins. 

A thin, delicate membrane separated from the pia mater by a 
space called the subarachnoid space containing the cerebro- 
spinal fluid. 



3. Subarachnoid 

trabeculae. 

4. Ligamentum 
denticulatum. 



5. Pia mater. 



Structure. 



White fibrous tissue 

with very few 

J Partitions of the subarachnoid space by prolonged extensions -^ elastic fibers and 

I from the arachnoid to the dura mater. i covered with 

I endothelium. 
Narrow bands between the anterior and posterior nerve roots at- 
tached by their inner edges to the pia mater and by their outer 
denticulated edges to the dura mater. 

A delicate, vascular membrane investing the cord and dipping 
down into its fissures. 

W b^ te fibrous tl^^'^uc 
6 Filumterminale -I Prolongation of the pia mater downward enclosing the central , ^nd a few nerve 
u. X iiuiii tcxuxiiiaic, -^ canal and a little gray matter at its upper end. ' g„iig 



^ 



Divisions. 



1. Per- 
ipheral J 
white ' 
matter. 



Further 
Divisions. 



1. Fissures. •{ 



2. Nervous ^ 
matter. ^ 



2. Columns. ' 



Commis- . 
sure. 



2. Central 

gray ■{ 
matter. 1 



Two sym- 
metrical 
halves 
joined to- < 
gether by a 
gray com- 
missure. 



Subdivisions. 



Location. 



Description. 



! Short, wide and does 

1. Anterior. •{ Median. -| not reach gray com- 

1 missure. 

I Long, narrow and does 

2. Posterior. -^ Median, -i reach gray commis- 

I sure. 



1. Anterior. 



2. Lateral 



I Between 

■^ anterior 

I horns. 



Between 
anterior 

and 

posterior 

horns. 



Between 



3. Posterior. ■< posterior 'i 
I horns. I 



1. Nerve fibers of 
varying sizes and 
neuroglia. 



White. 



1. Anterior horns. 



2. Gray commis- 
sure. 



3. Posterior horns. 



Floor of the 
anterior 
fissure. 

"Wide and 

do not 
reach the 

surface 
except by 

roots. 

Partuniting 

gray halves. - 

Contains 

central 

canal. 

Narrow 
and con- 
tinue to 
the surface. 



1. Direct pyramidal 
tract. 

2. Anterior radicular 
zone. 

1. Ascending lateral 
tract. 

2. Descending lateral 
tract. 

3. Mixed lateral tract. 

4. Crossed pyramidal 
tract. 

5. Direct cerebellar 
tract. 

1. Lateral (Burdach). 

2. Median (Goll). 



Narrow, transversely „, 
band. ] Nerve fibers. 



1. Nerve cells. -^ Multipolar. 

n T.X -., I 1. Medullated. 

2. Nerve fibers. ^ 2. Non-meduUated. 

„„,.,. . I Modification of the 

3. Substantia spongiosa.-<j neuroglia. 

I Ground subst an c e 

4. Substantia gelatin osa.<^ around central 

canal. 



THE TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT. 



119 



NERVOUS SYSTEM —Continued. 



Organs 



Divisions. 



1. Anterior 
oral lobe. 



Desckiption. 



Structure. 



7. Pituitary 
body or hypo- -{ 
physis cerebri, 



2. Posterior 
cerebral lobe. 



Larger, darker than the posterior. For 
some time remains connected with 
the oral cavity. Later its connection 
atrophies and disappears leaving the- 
anterior lobe separated from the buc- 
cal cavity. The single primary tube 
by division becomes the tubular 
acinL 



Small and of a distinctly nervous type 
in the lower animals. In the higher 
this character is lost, the lobe remain-- 
ing rudimentary. Outgrowth of the 
primitive brain. 



1. Tubules. 



1. Basemeut m e m - 
brane. 

2. Polyhedral epithe- 
lium. 



Fibrous and elastic 
tissues. 

Small pyramidal 
nerve cells. 



8. Pineal gland 
or epiphysis 
cerebri, the . 
remains of a 

primitive eye. 



1. Alveoli. 



Tubular compartments held together 
by a framework. 



2. Framework.^ ^i^^J«^"^»g_*°^ e^a«"« 
3. Lumiua. \ Colloid matter. 

1. Framework. < 

2. Nerve J 
elements. ] 

3 Cavitv J Lined by ciliated col- 
' ' 1 umnar epithelium. 

1. Basement 
membrane. 

2. Epithelium. ^ Polyhedral. 

Calcium carbonate. 
Calcium phosphate. 
Magnesium p h o s - 

phate. 
Ammonium p h o s - 

phate. 



3. Brain sand. 



4. Corpora 
amylacea. 



1 



Round masses with 
concentric stria- 
tion. Respond to 
starch tests. 



9. Olfactory 
lobe. 



2. Septa. 



1. Tractus 
olfactorius. 



2. Neuroglia. -| ^^at™ ffSo ."' 



An enclosing sheath I 
or ring of nerve<; Medullated nerve fibers, 
fibers. 



3. Gray matter. 



An oval area richest I 
in the dorsal part of^ Same as cerebral cortex, 
the tract. j 



2. Bulbus 
olfactorius. 



1. Whit© J A flat ring of longi- I ^t ^ n a j ^i, 

matter. 1 tudinal nerve fibels.i Medullated nerve fibers. 



2. Neuroglia. ^ ^trmer^men" ^' 



3. Stratum J 
granulosum. | 



4. Olfactory 
glomeruli. 



5. Olfactory 
nerve fibers. 



with branches and*> Nerve cells. 



Large pyramidal cells 
" " bi 
axis cylinders. | 

Dense tufts of theter- 1 

^ro'Slsls^^^of^^ thei Protoplasmic branches of nerve cells, 
pyramidal cells. | 

Arise in the cells of i 
the Schneiderian 

membrane fro mj Non-medullated nerve fibers, 
whence they pass 1 
to the cerebrum. i 



120 



A CONSTRUCTIVE METHOD IN HISTOLOGY. 



OEGANS WHICH APPAEENTLY AJRE NOT TUBULAE. 



Organs. 



1. Spleen. 
Plate XTJ, Fig. 1. 



2. Adrenals. . 
Plate XLII, Fig. 4. ^ 



Divisions. 



Steuctuke. 



1. Capsule. 
2. Trabeculse. 



3. Malpighian 
corpuscle. 



4. Spleen pulp. 



5. Splenic artery. 



I Connective tissue mixed with smooth muscle surrounding the organ 
j and extending into its interior as a framework. 

J Prolongations from the capsule which unite by processes in the in- 
I terior and form the framework. 

I Spherical or cylindrical masses of lymphoid tissue surrounding the 
J branches of the splenic artery. In section the artery appears in 
] the center or at one side of the lymphoid mass. 

I A stroma of reticular tissue continuous with the trabeculae. Bed 
J blood cells and leucocytes in large numbers. Large, round, amce- 
] bold cells sometimes containing pigment granules and red blood 
I cells. Nucleated red blood cells. 

I The artery and vein do not connect directly by capillaries. The 
J blood passes out of the fine arterial branches and circulates in 
S spaces between the cells of the pulp and then finds its way into the 

I branches of the splenic vein. 



1. Capsule. ^ Connective tissue and smooth muscle. 



2. Cortex. 



3. Medulla. 



SxEucTUKAii Units. 



Desckiftion. 



1. Zona glomerulosa. 
2. Zona fasciculata. 

8. Zona reticularis. 

1. Cords and networks. 

2, Granglionic cells. 



-( Oval masses of cells. 

-{ Long cylindrical masses of cells. 

J Anastomosing cords of pigmented 
I cells. 

J Cords and networks of polygonal 
I cells. 

J 1. Nerve cells. 
] 2. Non-meduUated nerve fibers. 



Orgak. 



ORGANS WHICH APPARENTLY APtE NOT TVBJjl.AB,.—Conimued. 



4. Thvmus, 
Plate 'XLL ■[ 
Fig. 2. 



5. Tonsil. ^ 



6. Carotid 1 
gland. j 
7. Coccygeal I 
gland. I 



Divisions. 



Stkuctxjre and Description. 



1. Capsule. -{ Connective tissue surrounding the organ. 

2. Lobes. -{ Larger divisions of the organ united by connective tissue. 

Densely 
1. Cortex, -i packed with 
leucocytes. 



3. Lobules. 



Smaller divi- 
sions of the 
lobes united « 

by connective 
tissue. 



Follicles. 



2. Medulla. 



Loosely 
packed with 
leucocytes. 



Concentric I Remains of i 

corpuscles of -< early epithe- 

Hassall. | lium. 



1 o e j Stratified pavement epithelium perforated by twelve to fifteen orifices which lead into 
1. ouriace. <j ciyptg. 

^work^^ J White fibrous intermixed with yellow elastia 

^'bo^es^'^'i '^^^ ^^ eighteen round masses of lymphoid tissue arranged around the walls of the crypts. 
4. Crypts. -{ Pockets formed by the surface dipping down into the interior. 

At the upper end of the common carotid and in front of the apex of the coccyx are two small glandular 
looking bodies composed almost entirely of plexuses of blood vessels derived from the carotid and 
middle sacral arteries — the whole is invested by connective tissue. The blood plexuses are covered by 
one or more layers of granular, polygonal cells. 







Ant«v(ovvA/h«t€ 




VoLt^ynoYftkoui Celts. 

CQxdv^i CoV€ Of 
w/itt« YnaiiiY. 



J/euYaxei. 
AntQYiov Incest An 

^Dty«ct ytfYAtniciikl 
tract' 

^. scene/ «nff' 
aY^t«yo-tat«v»«/« 

i><ct C^Y^i^^UaY 
Cr o SS«<^ />yva»Mc^a^ 

^ ColumT\ ofHuYclach. 



Q-yau CornTnt s$u y « , 

Sj>mai Coyd. 

OryoTis wKtch (x\>^CLY6hilif aye not ta^^t^or. 

PLATE XL. 
Diagrams of Beain and Spinal Coed, 



SZSL "Poster ccy kom. 
\Vtfin. 



s*/»tum. 



121 



122 A CONSTRUCTIVE METHOD IN HISTOLOGY. 

lined with a simple epithelium like certain other tubes. Functionally the 
tubular character is not so clearly marked. The brain is composed of 
an external layer of gray matter which generates impulses and an inter- 
nal core of white matter which conducts those impulses. In the spinal 
cord this arrangement is reversed. Both are enclosed with a covering 
of bone. If both the brain and cord were solid, that is, had no central 
canal, an increased or decreased blood supply would produce pressure 
upon nervous tissue and cause a termination of nervous phenomena. A 
central canal is essential to the volumetric increase and decrease of these 
organs; so that, although the functions of these organs do not depend 
upon the specific character of the tube as in other organs of the five tube 
classes, yet structurally the tube plan is essential to the successful per- 
formance of function. (Plate XL, figs. 3, 6.) 

The thymus in its early development is almost like an epithelial gland 
and during that stage of development would be classified among the tube 
structures of the body like any other true gland : but about the end of the 
second year following birth it begins to retrograde and when the age of 
puberty is reached an adenoid structure has displaced the epithelium and 
atrophy reduces the organ to an inactive condition. Therefore during 
its active period it belongs to the secreting glands and to the one coated 
tubes. During its retrogressive period it is not tubular. (Plate XLI, 
fig. 2.) 

Apparently the spleen does not belong to the tube organs. However 
it seems to be a vascular body structurally and functionally, for if its 
vascular tubes are not considered in its plan of structure the remaining 
parts are reduced to blood cells. Its trabeculae of smooth muscle sug- 
gest a relationship of force pump to the liver and the spleen would belong 
to the three coated tubes. (Plate XLI, fig. 1.) 

The lymph nodes are composed of masses of lymphoid tissue around 
which are channels through which the lymph passes. These channels 
or sinuses are lined with endothelium which also lines the inner surface 
of the capsule and outer surface of the trabeculae ; so that the channels 
are widened parts of the lymph vessels within the nodes. This places 
them under the one-layer tubes. As far as function is concerned the 
parts outside of the channels are reduced to the functions of lymphoid 
tissTie or leucocytes. (Plate XLII, fig. 5.) 




Stroma- 



S ^Uan 










Thymus. 

PLATE XLI. 

DXAGBAMS OF SpLEEN AND THYMUS GLAND. 



123 




&$u[e 






ona 



TfittC^t^avis 



Ad'^ffnuL. 




Lym|.K V€SS^/. 






^-<- 



^^c.. 



CVOSS Section- 



PLATE XLII. 

DiAGBAMS OF THE AdBENALS AND LtMPH NoDES. 



124 



THE TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT. 125 

The adrenals are composed of cells arranged in different ways ac- 
cording to the zones which characterize the structure. A tube plan is 
not sufficiently apparent in these organs to place them under a tube 
system. (Plate XLII, j5g. 4.) 

Thus a general survey of the animal body and its contents convinces 
one that the tube is a fundamental structure. It must be taken into ac- 
count in the pursuit of anatomical, histological or physiological investi- 
gations. If we study such subjects without bearing constantly in mind 
the tube in all its variations and purposes we will study them separated 
from their actual connections with the systems or organs as they really 
occur. In most instances, if not in all, the phenomena which appear are 
due to tube influences. In thinking of the functions of the viscera we 
are obliged to associate together both the tubular structures and the ac- 
tivities of the cells of these structures. For instance, if we think of 
some secretion and omit the presence of the tube, we simply think of the 
production of a chemical substance which has no means to direct it to 
any fixed point. We must, therefore, leave it to be dissipated without 
serving any useful purpose. As liquids flow in the direction of least 
resistance, the presence of tubes is not only essential to direct them, but 
also, by cell activities of their own, to add or subtract from the original 
liquids and thereby to increase their efficiency. Perhaps all secretions 
are modified in character by their progress along the tubes which pro- 
vide for their means of escape and are ineffectual until acted upon by the 
whole length of tube from beginning to end. 

Again the non-motor and motor characters of tubes are essential to 
our understanding of the disposition of products after they are once 
formed. The body products are manufactured for a definite purpose 
and that purpose is defeated without the presence of some motor appa- 
ratus in those tubes in which motion of contents is required and the ab- 
sence of such apparatus in those tubes in which motion of contents is 
not required. It is necessary to think of all tubes as living tubes and 
not as lifeless conduits. Tubes resemble each other, since they are often 
engaged in the same business. Their structures are similar and they 
can be constructed by means of similar parts, of which they are all com- 
posed. This act of construction supplements the mental act which is 
required in their analysis. 



126 A CONSTBUCriVE METHOD IN HISTOLOGY. 

COKSTKUCTIVE DiAGKAM. 

In the large, curvilineal, constructive diagram which follows, the 
five classes of tubes are represented by ^Ye concentric circles. In 
these circles may be found drawings of microscopic sections of nearly 
all of the tubular organs of the body— sixty-five in number. The cir- 
cular plan of the diagram suggests the circular character of transverse 
sections of tubes. By arranging the microscopic sections of all of the 
organs of any class of tube, side by side, in one circle, the number of 
organs, the layers and coats in common, the structural characteristics 
and the plan of construction may all be readily seen and understood. 
It will be noticed that the largest circle is the circle of the one coated 
tubes. It comprises the largest number of organs, thirty-five in num- 
ber, and these organs are mostly the small tubes, chemical in function, 
non-motor in character, which constitute the secretory, excretory, and 
sensory organs. Microscopic sections of structural and functional units 
of many of these organs are very much alike in appearance. Thus a 
cross section of a single acinus of one secreting gland is very much like 
a similar section of an acinus of any other secreting gland. If we 
take acini from all of the secreting glands of the body and place them 
side by side the differences between them are not always sufficiently 
apparent to enable one to distinguish, without doubt, one gland from 
another. For this reason many of the sections in the circle of the 
one coated tubes closely resemble each other. Next in numerical im- 
portance and therefore in size is the circle of the three coated tubes. 
It comprises nineteen muscular-motor and muscular-ciliary motor tubes. 
These tubes are the large tubes of blood supply for the viscera, of 
gaseous income and outgo for the lungs, of outgo for the chemical 
products of glands and of exit for the products of conception in the 
female generative tract. Next in numerical importance and size is the 
circle of the four coated tube. It comprises the eight parts of the 
alimentary canal which can be identified microscopically. The tube, 
as a whole, is muscular-motor. The functions of digestion and absorp- 
tion are performed by the small one coated tubes which enter into the 
formation of its lining. 

Next in numerical importance and size is the circle of the two 
coated tubes. It comprises only two organs— trachea and large bronchi. 



THE TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT. 127 

Eings of hyaline cartilage distinguisli this tube from the one coated 
tubes and supply the means by which open tubes are maintained. These 
tubes are ciliary-motor and the only large tubes with no muscular coat. 
The next in numerical importance and size is the circle of the one layer 
tubes described around the common center of all the circles. It com- 
prises all the capillaries, but as these are all alike in structure and 
function they may be considered as one organ. These tubes are non- 
motor and the simplest in structure of all the tubes of the body. Thus 
the diagram displays the numerical importance of the five classes of 
tubes. That class of tube which comprises the greatest number of 
organs is naturally the most prominent in the welfare of the whole body, 
and this will be inferred from the number of chemical tubes in the one 
coated circle. In fact the animal body seems to be a colony of secreting 
glands composed of myriads of chemical tubes the products of which 
are essential to the continuation of life. It also indicates the mechanical 
importance of the tubes of income and outgo which serve in the capacity 
of carriers to and from the chemical tubes as may be seen in the 
three coated circle. It further indicates the importance of a combination 
of chemical and mechanical tubes in one as seen in the four coated tube. 
It indicates the value of a two coated tube as a functional tube ; since it 
comprises only two organs. Lastly, it indicates the simple structure of 
the one layer tubes. At the left of each microscopical section are the 
model numbers which, arranged in the order of their occurrence from 
below upward constitute the building plan. The outlines of the two 
leaves of the accompanying case correspond in numbers and arrange- 
ments with the drawings of the diagram; so that the diagram, outlines 
and models furnish a working system of tubular construction. As all 
of the microscopic sections of the tubular organs of each class are placed 
side by side in one circle a good opportunity is afforded for comparisons 
in structure. A glance is sufficient to show differences and resem- 
blances. It will be noticed that the diiferences are, for the most part, in 
the linings and the resemblances are in the coats external to the linings. 

That the only tube in the body having a coat of striped voluntary 
muscle is the upper oesophagus. 

That the muscular coats in other situations are smooth muscle. 

That the majority of muscular coats have two layers of muscle- 
viz., external longitudinal and internal circular. 



A CONSTRUCTIVE METHOD IX HISTOLOGY. 

That the following tabes have coats of three layers of muscle: car- 
diac stoiQach, uterus, lower ureters, bladder, vas deferens. 

That the following tubes have coats of one layer of muscle: small 
arteries, veins, lymphatics, medium and small bronchi. 

That in muscular coats of three layers the external and internal are 
longitudinal, the middle circular. 

That in muscular coats of one layer the muscle is always circular. 

That all large tubes, excepting trachea and large bronchi have mus- 
cular coats. 

That small tubes have no muscular coats. 

That secreting glands are found beneath the epithelial coats of the 
following t^n organs : oesophagus, duodenum, medium bronchi, small 
bronchi, trachea, large bronchi, nasal duct, lacrimal sac, tympanum of 
ear, skin. The conclusion, therefore, is that secreting glands do not 
occur in the walls of the majority of tubular organs. 

That in most mucous membranes mucus must be produced by mucous 
cells of the epithelial coats. 

That the structure of all of the organs of each class of tube is essen- 
tially the same. 

That all tubes have an epithelial coat and aU, excepting the one layer 
tubes, have additional coats according to the function performed. 

That the five classes of tubes are developed from the one layer tube 
by tissue additions. Thus : 

1. One layer tube— epithelium. 

2. One coated tube— epithelium plus a base. 

3. Two coated tube— one coated tube plus cartilage. 

4. Three coated tube— one coated tube plus a muscular coat. 

5. Four coated tube— three coated tube plus a muscularis mucosae. 
That all tubes are motor or non-motor. 

That chemical tubes are non-motor. 

That mechanical tubes are motor. 

That there are two forms of motor apparatus, viz., cilia and muscle. 

The diagram, therefore, calls our attention to a certain class of facts 
which we are likely to overlook in a study of separate sections and pre- 
sents to the mind a picture of correlated parts which is very important. 




CONSTEUCTIVE DIAGKAM. 



SECTION 3 
TECHNIQUE 



The Prepaeation of Normal Tissues. 

Unless distinguislied by the presence of some normal pigment, proto- 
plasm, in its various forms, is nearly colorless. The differences between 
one form and another are not sufficiently marked to enable one to iden- 
tify them as they appear under the microscope without considerable ex- 
perience. The examination of tissues immediately following their re- 
moval from the body reveals them in their natural state and doubtless 
is the best method to pursue ; but in such specimens slight differences in 
protoplasmic densities are about the only means by which parts can be 
identified and the detection of these differences requires a much wider 
experience in microscopic work than most students have had. Some 
preparation of normal tissues is, therefore, necessary in order to bring 
before the eye the different parts which are under observation and, 
furthermore, to preserve them for future study. The preparation com- 
prises several processes, each one of which is essential to the next one 
in succession. The processes may be outlined and employed in the order 
given below. 

C Killing, 4. Infiltration, 

l.^ Fixing, 5. Embedding, 

V Hardening, 6. Cutting, 

2. Decalcification, 7. Staining, 

3. Dehydration, 8. Mounting. 

Killing, fixing and hardening: These three processes are usually 
accomplished by the same means. The object, in all cases, is to exhibit 
tissues in a condition which approaches the natural as nearly as possible. 
The more rapidly cells are killed the less liable are they to undergo 
decomposition changes which evidently must begin as soon as metabol- 
ism ceases. No one has ever seen a living cell as it actually exists with 
its subtle chemical and mechanical activities in operation. No one has, 
therefore, an adequate knowledge of what is called its natural or normal 
existence. The cells which we see under the microscope are merely the 
architectural structures within which a vast performance of unceasing 

131 



132 J. COXSTBUCTITE METHOD IN HISTOLOGY. 

activities has been going on according to the requirements of a multitude 
of cell commnnities whose innnmerable interrelations render possible a 
living body. They are the monuments of individualities which are gone 
forever. TThat is called a cell as it is seen under the microscope is no 
more a cell than the dead body of a man is a man. 

Killing : This consists of various freezing processes or of those proc- 
esses which follow the actions of chemical reagents upon tissues which 
have been immersed, immediately after their removal from the body, in 
any one of the numerous solutions which may be found in the outlines 
at the end of these preparatory descriptions. This process brings us as 
near to the dead, unchanged remains of cells as it is possible to get and 
the knowledge which we have of them is derived from the study of these 
remains. Many solutions of this character are in use according to the 
particular study which is to follow. It is better to become familiar with 
the actions of a few of them and depend upon these than to select one, 
at random, from a large number concerning which we have no practical 
knowledge. 

Fixing : This consists of slight degrees of coagulation brought about 
by chemical reagents by means of which minute structures are held, as 
nearly as possible, in a natural condition. Solutions which kill gener- 
ally fix at the same time. 

Hardening : Prolonged action of the chemical reagents upon tissues 
completes coagulation processes and increases the degree of hardness 
of the tissues. It furthermore renders them still harder by some chem- 
ical changes which are the results of a slow and long continued applica- 
tion of the chemical elements of the reagents to the chemical elements 
of the tissues. This process is necessarily a slow one if the best results 
are desired. A rapid hardening process shrinks tissues to such an ex- 
tent that they are often misleading in appearance and valueless as struc- 
tural units. Many hardening formulae have been devised, a few of 
which may be found in the following outUnes. 

Decalcification: This process removes the inorganic salts from cal- 
careous tissues by the use of some acid solution. This removal of salts 
is necessary before tissues are hardened. Of the normal tissues this 
process is mostly confined to bone. It is not, however, an important 
process in the preparation of bone sections, as much better results may 



THE TUBE AS A STRUCTURAL AND FUNCTIONAL UNIT. 133 

be obtained by grinding dry bone to the required thinness. It has a 
greater value in the preparation of calcareous tissues of a pathological 
character. The usual formulae may be found in the outlines. 

Dehydration: By this process water is removed from the tissues. 
This is necessary in order to prepare them for the succeeding processes 
which are of such a character that the presence of water would defeat 
their accomplishment. It is one of the most important processes em- 
ployed in the preparation of tissues, for the reason that they contain a 
large percentage of water when the preparatory processes begin and are 
mounted in balsam, which does not mix with water, when those processes 
end. If, during the dehydrating process, the water is not entirely re- 
moved, the sections will become opaque and unfit for examination with 
the microscope. The dehydrating reagent is alcohol. 

Infiltration : By this process the spaces of the tissues are filled with 
some liquid— usually melted paraffin or celloidin— which hardens either 
by exposure to a lower temperature or by the removal of some constitu- 
ent of the liquid in which the solidifying substance is soluble. Filling 
the spaces with these substances in a melted condition or in solution and 
allowing them to harden render the tissues practically solid, in which 
state they may be cut in very thin sections. The methods employed may 
be found in the outlines. 

Embedding : By this process infiltrated tissues are enclosed in melted 
paraffin or thick celloidin which harden and firmly fix them to a block of 
wood or other suitable material manufactured for the purpose, so that 
they are firmly held during the cutting operation by razor or microtome 
knife. 

Cutting : By this process the embedded tissues may be cut in sections 
sufficiently thin to render all their structures visible under the micro- 
scope. Sections may be made by freehand cutting, but, in order to 
secure thin, even sections by this method considerable patience and prac- 
tice are necessary. Microtomes are much more satisfactory. These 
instruments are so constructed that sections of a definite thinness and 
regularity may be cut by an automatic mechanism. They may be ob- 
tained from any maker of microscopic accessories and are almost indis- 
pensable in tissue work. 

Staining : By this process the nuclei and cytoplasm of cells and the 

10 



134 A COXSTRUCTIVE METHOD lY HISTOLOGT. 

intercellular substances are sufficiently contrast-ed with their suiTound- 
ings to make their identification possible. This is accomplished by col- 
oring them with some staining solution which is selective in its action on 
account of the variations in the chemical elements of both structures and 
solutions. It would, doubtless, be better if staining processes could be 
abandoned and tissues examined just as they come from the body ; but, 
at the present time, this is hardly practical, especially with beginners. 
The usual staining foimulge may be found in the outlines. 

Mounting : By this process sections, prepared as above indicated, are 
placed upon glass slides, enveloj^ed in Canada balsam or some other suit- 
able material and covered by a cover glass. 

The satisfactory study of microscopical structures of the body de- 
l^ends largely upon good, clear, well-stained sections. A poor specimen 
leads one into false impressions or into none at all and if we are com- 
pelled to derive our knowledge from it, that knowledge is quite likely to 
be modified by imagination and conjecture. The field of the microscojK) 
is small, especially under high powers, and moving the section about 
upon the stage in order to see all parts of it produces a moving picture 
which is not calculated to establish lasting impressions. Such kino- 
drome effects defeat the very purposes of our investigations. 

In the following outlines the ordinary processes and formulae em- 
ployed in the preparation of normal tissues are given, in a concise foim, 
to facilitate the selection of suitable reagents. They are given in the 
order of use, beginning with the killing, fixLog, etc., and ending with the 
mounting of sections on shdes. 



▼ htf Pva^gvatton o^ /^roytnal TtA4u.es 



*¥0^fSi«i 



R<?Qyg»it5- 



foTmu lav ■ 



.^HJdi tn t/tf $^krft9n Qi<\ K<<^fgwt- 



lMuUhys 
FLuid. 



i.Orths 
fluid. 



Potassium Bichfoma-t^ 
Sodium Su/Lhate . _ . 
Wof«f 



_loocc 



IZenkers 
Fluid. 



I rti.it\f 
an d 
Hardchtn^. 



PoYtnalitxe 



5.Ra6^ls 
^ Solution. 



i.flentmin/s 
holaiion- 



7AUoho( 



iosmic 

Acid. 



Potassium BichyotttaU J.iyrams. 

Sodium Suif,hatQ /. 

Wafer . ,/oocc 

Fotmaldih^di ^0^ Of ioluiion /OCC 

Add the foYynaldefiJfde^ol.foifie 
Bichvomoie atiheiitne ojusitif. 

Pofassiutn eichyomaig 'J.S'gYams 

Sodium Suhhate . /♦ 

CoYtoSi^/t Suliimat'i. . 5". 

Siaciai AC^Hc acid _ . , SCC 

Wafc*-^ /OOCC. 

Addihi acid aiiime of usitif. _ 

iroYmaldthjfdi ^0^ a^SoL. lOcc 
Sodium ctiloYide O.yS^oa.SoL 9occ 

chromic AQido.ii/cQo.SoL. ^oqCc 

ToYtnic Acid. ^ St>voj,s. 

Add ihe Fotmic Acid at 
•tfn iirni oj usim^. 

OSmic Atid i^ (^. Sol sec 

ChYomic Acidl^Oo Sot Jocc 

Siaciat acetic acid ice 

Mix ai ymded. 



'^LattiitottfutHQfcltnSivioti^htvvtekt. 
Change often. 

MAif ii used -for all i(6<ae«.//a><^«n 
f0Uvio St* dajfS.Modeyaie heat- 
hiksitns thi ftYQCfSS. Change tf,t 
Solutioy\ Once' on< of t-A^ 
^«.st of the kaydtnitig' fluids 



Matf ^ used .for a tHiSSu«s.Rai,i'<t. 

Hoyt^efx Stnatl jjiects X^-</&houYi. LarfQ 
J t/cces StwfYot dajs. Remove l,v9cij,itati 
0{ m.eycuYie SaLt ^^ addi-fion of oSfo 
rihct.Jodint to the alcohol in wAicA 
the tissues are byiSeyved 



AQiy ^e used -f ov ail tissues. Hafyid. 
' Best foY n«yvoa<$ tissue. 

Alimeniars C'^nQl,CYn^ysoi.LaYjnr. 
tYcichea, Cunfs,uieyus,itadde*, 
UYeieys, owariiS, Smooth hiuscU. 
Raftid. Sood. 

penetyatiS Slo^^ljfHas noVo/u« 
in Lay^Q hiices. Best-foy $tudjf 
of Karj^okinesis. H&yden v«yy 
Small Lieces i.fhouys to 3 d<i^s. 



iSkin, tendon, glands, Strihed muscle, 
Hoyden in the Successive frades to 
jtYewent ShYinkaigre-'reyM Ix^dYi it\ 
each Suf^icitnt {oy Stnatt lieces. 



O.STo ao. 6ot. 



Besf fav wcvvc fleers. TMot 
one to two daq£. 



ZV/aShinf. , 



/.Wat«^ 



A^ter haydenin^ in Bichromate oyMe.ycayic Sotutiont, tissues Shoutel ^e 
klaced in vuater foy the buy/>ose of vemovtny' the Coior and ialts wfttcA 
ha\e Ireen dejtosited during the tvocccs. As a yu^e it is l^etier to omit 
the y/t/QShinf kyoceSS inyteywouS tissue wAtcA Aat l-een hardened in 
MiJiUey'i fluid und transfer at once to alcohol. 



135 



ProcffS£ss. 



t^i'^g'^n- 



Pr;>/>^vgf<:oTi cf A'oyma/ ti&Sues. 



i-Sfcofcificaf/otj, 



Mor<.^l^ciA iiZ'g^ 



F O VjnuJ-jSui 



, fc-* V i.^;^l yi^ric Acid Sec 

I C fiance each d<i^ 4or {Our 
I dxLifS. WG.sh> Harden ihnic^ftol- 



Phloro^Lucin, .... /<^>n3 



L&An&^ . 



O-tlo 

tritricAcid. 



hitric Acid 



S"cc 
70 cc 



Wet? »•._'' * I 1 I r Jecc ^ 
f?i2fAcr e/ow. Wa5/?. Hctden 
in alcohol- giv*s ^ooo^ 



A Saturated acutous 
(So /atio n w i'tf/an exe e s f 

|/uivc^cn5 aftA€ S.ar7i€ time 



>fgtKod 



Tissues 



Smai( fcteCfiS should I*. f>Lac<^d 
inth* decaUififin^ soLuticn 
Qna'ftmain urjtti.s«ft. 
Wafi^ utiiiL yeoifint l% 
Ytmo\ed and then hay^dtn 
iTl aicohoLfhloYo^luciyi 
^rctects^thi acid dtcalcifiis. 

Hcifj/fn ip Ztukey, oyth oy 
aiccho i -W'as f-. ■ PLaci in 
the diCalCL-fc^ir^i soluiiost 
\ tkPii^ SQ-Ci.Vi/aSh ur.til 
r€a('£r,i is -rtrr.oy^ici and. 
thin kard€r* m uLcchiti. 



^H^hjfdi^iiQ n ^lAleohoi 



The yemova^ of vva^^f^om 
atltiSiues,y»fhich ho.Me Uzn 

haydcn^d C-y V^athtd, ii 
}iecc&5ayy in OYdiy tAat 



kfAJ-ivialS. 



^Infiiiratlon., 



iCeUQicin 



Pvo^nVofLOTi 



riU a La^g€ mouthed Iroitte 

kayti oj-siYong aicohoLand 
^iiiWs eth^y and dissolve 
in ii suf^icicvt iolulle 
Cotton iquri Cotton ^ood 
ftnk{iiy)tQ tnake athick 

thifiney ioLutiCM art )fnckdt- 



>'^P't-nO^ 



Yayct^in in iuch ^yojyoyito^ 
that the mLxture metis 
at air out SOC the 

'Suyyoundin^ atv^eih^/7C 

Best foy imall %Lccitnen& 
A ^ood Laranin Stove tS 

CSSCht/flf. 



Piace well hardtacd and d(t-.sdf<itid 

Lay^e SfiCiTn(tii ih thel oiiovntrto 

Solutions: 

/-Strong alcokoL artdS^M'Uts «f/»e>--^A*/^»4v2.fMs 

'^rbin CiUoidLn -l^' /»o«ri.| 

irhickey diUidin l^ - 

¥.siili t'nickey CeiUidL}^ 2sf ■■ 

SmaiL S^ecimeni ynat^ U infiityated in 

Ofcw hours. 

Place \htU havdittsd find <lt49Hf Vdled Slfea^f 

Sf.€etmcns ixithi foLLovtii^' 

t.Alcohol fS'%>-/0<ifc 4 -Zflfmtr^ 

2.ChLoYO-Coyyri or qU oj CidaY. jL' iV 

3. Payaf~ ir\ Iratn - - /" * *• 

^.Vataffin l^at/i /--i 

5" payoff ih i-uth . . J 

mthi Uace of A<i-3.atath CfCrUrifirr-, 

iaittytkitd Vnith ^ftfaff ih teey kt iLitd, 
\Mltk cte/vaM't'a^fi- 



136 



Pret>Qtatf«on of /^ovmat Tissues 



Pvoegfsgj- 



MotKoc/g. 



Py€{»a»atton 



It is )nsC9SSart/ io^asten culloiclin 
Sj,QCimci\s to ai-ioek /n ovc/e** to 
Cut thiri Sictcom witAokntf «. 
\/ulcar>izeci Ftl«r vna*/ ^c oi^tamtid m 
the. rnayk«t and <s ^ooc^j irut 
SatiSfaciofj/ i-^ocKs ma^/ /c maf^« 
/ Blocks \fyom irass-vuood l\f^X^-v inch<iS. 
i Thc^ will not Stain alcohol to 
anjf £Xi«rtt^ and bi-oy/icls a Solid 

subhoyf. one end oj thd ^IqcK 
SH6uld ^e Sa\A/sd ^/& inch ^yom 
one Stdn and Yv inch deit, ^ov the 
Stvin^ \lMhich attaches ih« ta^ 
ujyon w/itc/j is \n/rHtenthe name 
or numley of the Sf>ecirney%. 

Tak« 8**ff ^af>i'f^'/i.XS.'/i ine.h«e and 
■foLd it aioin^ ihi lines o^ thedia^ram 
6-iiow and <i ^ox \AiiH Irf i'nac<9 w/j<c/j 
y^m hold meliid hQ\rA.(^in. o\r t}A/o 
1'^^ ' ' L Sha], c W 

=<a»ijr «» th«cl«ay 
tnajf ie k> laced 



PYOCass 



(>.Er\->l;^eddir\^ 



Atoids. 



t& 



:^ 



~. Sot 



^ 



V, 



ijL 



i.rnezin^.. 



iCuttm^. , 



/. Razor 



iMtcrototne ' 



■ ■ ■■ — • "pyn a4.(4r 

Sur-face wet \A/(t/i §i«/C«»*ih« thas- I ' 
and a mo Id Ynaj/ ke. made \Aihich vjiil 
f\otd m«lt<id bara^fiH- 

These, iroXeS andmolds may i,e used 
-for ^ith^r f>a.va^^iri orctliotciitt. 

Tanks of COj under It-fuid j,Ye&suYe 
Tnaif tre ei-taimd -frotn COj tnanufoctuvfts 
Or tnaketrs of tnicro$cof,ic Suf,f,/ies: 
or a imaU ethir Bkraji aUaratus 
\naif ie o&iixined from an<( micro scobe 
inake r. COt, Lithe ^uickat o.nd ^4sr 

Atytf ^ood razor ^rotind jlat onthe 
lower iide o$ ittS held in f^Qniion 
to cut towdrd ^ou.inthe &tiid«/ of 
^reih ij>ecimehi o ^ood douUe khi{e 
is e&iehfia/. 

Atnechonicol de\/ice fov CuHm^ 
Sficttoyjs of aniform ihinnesi. 
If anum^fiv of Seciion^ ore to l-e 
Cut an auiomoiic microtome ts 
thelreit. rketf are all so Con&iut^tid 
that ieciioni of any desired 
ihinneSi may ^e ohio-ined 
Consiiteni \^ith the character atthe 
titsuit. 



Place a little of the thickest 
celLoidin on ih<ie.nd of a ^/ock . in 
±hL& arrani^e the Sfoecimen and 
^our o\fer it aliMyal SuUlj of 
the Same celloidin. Set itto one 
Side for two or three minutQ.s. then 
|./.ace hlock in 80^ alcohol Wheva 
■• it ma If r«.ynain untU tt is neacied. 
SeciconS Vna^ Ire made after C hoitrs- 
Ov Skecimeni rnoj ie etnieddcd ina 
iiolid Uock l(f yMyaUm^ a strik of stiff 
^oLer around t/ieend of the Hock 
UtliOS^/tn^ ittohroiectai-oX'e theSbecimen 
anciiillin^ the vvet/ thaifo?yn9cl\A/ith 
CelUidin and Liaciti^ in i>of^aicohol 

Fin the iroxes ov molds ^/j^ull of 
melted jaaraffin.AUo-w the Surface to 
Btif^Qti ijfCooUn^' Place sf>ecimey} in 
b¥Qb«v hosition neoY one cndJUl 
khe &OV&S or molds full of hisitkd 
boroffin and Set them aside tocool. 
'w/}cr» so/tW tear off the bahet- an<^ 
fYirn the hardffm (rlocks. Theif ore 
iihinyaad^ fov Cutting. Or SYnall 
5fcecim«ns \ti«'tf Ire eniUcLUd m o 
k'tock of bai-aff tn Irif tneitin^ the 
Cepiral Lhrt of owe end wiiha /lotwiVe 
qnd introducin<^ the sheciyncn 
into the. rnelted blace and aKowinb 
it U Cool. ^ ' 



P<ac« s^ec<ni«n$ on |><at« of fM<2in^a|,urafi/5 

and cover them w?// wit/i iufar ialulion: 

A \9um ACacia.iQiYafns\T>\Loaf iuiav lifir'ms. 
"•]wat«r fo<:c (*»twafe«> ijio^c. 

Addtif,ayH ojA foFofB. CarloUcActd o.Sfr'ms. 

place H>ecimeni freivieen pieces of 
hardened liver or jtithand cutiectiam 
Irjhand. Cut t,ection'*\NiihthedouUe 
knife vw«f WitA y/mater from anyfreih 

T^« iriock Of wood orftoraffin uj,on 
vvfitch oirv/iihin which the i,j>eciYnen ii 
em^dded Li f,laced in the jaw of the 
ynicrotome and itctiom of 
unifornt ihinntii are Cut.Thekttije 
&houlcC Iri kcjlt w<t wit/t So% 
a^coKo( when Cutting celloidin 
Sections and dY«f wh«n 
Cutting paraffin %ectioni 



137 



P<re f.QVQf/or5 of hQ-ftnat Tissues 



S.Pr5S«^Vtn$ 



Sictions 
toSUdi. 



Celioidin 
Stciions 
to %lid^. 



CdUoiditi Hocks.^Majf ^« kc^f in iOfv alcohol inde-finiUij. 

Celloidin S^ciionsJMatf U Keff in aicohol,SltfCerinf,\/vati\r,c&ua(J>ayts^ir\deji-niteijf 



Alirumiit. 



I j>isiiUid 



t^f fkUutnin- locc 



A itnall dvoy iS YuU^ed evettiy on acUah Stidi. A 
3iCiion it Llacid Uhon iiii.nd held o'vef a-ftamt 
until the haraffip is meUxd. The aUrumin is f 
Coa^ulalkd and the section is^ixed to tht slide. 




I minutes ov unti 



>X4it 



eded 



yTahaYiQSQ ^^^ ^ litili ^/^cchihc o^^^m/h oh a clean sUdi and />(ace ih an ovcn 

Miihod- \^^ 7^*'^- <^^tH dyy-rh^n ust the v^aier hieihod ai-o^e descyi^ed 

ov wiihi/te addiiioh of one drof* of ^l^ayim aUumin to iocc 
I of \A/ateY. 

ColUct Calloidin Siciiorts ott$iyif>s of jta/>«y ^5 ^yessin^ them uf^onthe Uade o^ 
the knif«. Pa<n^ac/car7 ^ias& &Lid9 y^ith \iey^ thin Celloidin, place the ^o.^ey 
siyijiS NA/i^A Section side down onihi ihin dyied lajfiY of celloidin and a Utile 
^ressuve wi// fnakeihe iQciions ac/Acfe ioihe celloidin. 
Remove the j^ajxiY &tvil>$ and Kee/. the Siciiom tnoist 
w<t/i 70?o aicohol. 



I Hansen's 
Hematoniflin. 



Il.^iainin^. 



Stains 



FovYnulaje. 



pye^arf^tion 



iDQla^idd's 
HetnatoVfltn- 



$Ol.A- }^*An\aiotyUn I^ratn. 

\ Alcohol /O" 

Sof. B i P**^***'' Alum _ a lo^m. 

' \ Hot vvatc*- ^ .ioocc ' 

SO(.C. [potassium peftnanponati.J^fom 
{Distilled Wat«v.- l^cc 



Hcmato)U/(tr) ^^vams 

Atrsoiuid AUohoi locc 

^af.Qc.- Soi. ammonia alum., ^oocc 

Alcohol fSfo /oocc 

S/j^cif/w /oocc 



^^iey I'fbauys standing tnit in a 
^oycelain dish Sot.A and So/. S 
Add S CC of Sof.C and with 
Constant Stivtinp S-oil one 
minuta. Fiiiey.This stain 
ynaif (re used immediately. 
It §ive£ ^ood yesuLts and 
is easily and oatcklj/ tna.de. 
K«e/,< wc«. ^ 



Oisso'v^ tli< ^ema^oky^<n int/ie 
ai^&olute alcohol f add the 
alum Solution, Ut stand in 
an ofen vessel *^ day g^ jitter, 
add the 9S^ alcohol and 
^IjfCeyine.AfteY scveva/ 
dajfS filthy a^in.Thii<,tain 
Vnajr i-« used hure ov diluted 
ahd^tves ^ood veSults. 
K<e/>S vw«U. 



138 



Preyciraiicin o4 fsoYtnat Tissues 



stains 






FoytTSutag 



HQYnaioXt^Lin ._ l^Jran^ 

A^so/at:e aicohoi.. /o<^^ 

Potash alum /o^ratm 

Dtsfi^^'dwctsv loocc 



±i:Jgp£i^JU£LliJL 



osssolvc th« U^matotidin in th« Qlcohoi, 
thi Qitim iniht wote** and mcK- 
JEX^oSc io li^ht and aiy iH-dai/s vv/»«n it 
s|i8r«ac/y i:otdi:<iv and use- Stain Sictioni 
'/j.hout. If ow«»-56itnc£< vwas/i inHCL^/odYoj'S. 
to loocc of 10% alcokol' 



HirnatotjfUn. 



Hetnatox^Un ^ .... ibyatns 

Potash alum ._- - -, -. i^YCttnS 

fii-^oluie alcohol /oocc 

Di$tille€( wafcf loocc 

Sl^cerine loacc 



Hihiaio)ijlin. 



LPal-Wi^itt 
Hitnaiotjfhn. 



7H«>nalumj 



HcmatoXJflin .... ,_ 4(5yams 

AlrSoiuta alcohol _ ^ , , . ^occ 

Sljfccvine J iocc 

Oisiille^i vvafci- | ^occ 

Slaciol acetic acici Jcc 

IMemaioXylin '^^-^^ 

Air&oU(te alcokol locc 

Sat ■ Of,- ^oi Lithium Car^onate^^Tcc 

oUtaUd v^ateY .- 'Occ 

At/x $hoyiljf /rcjoYe usin^. 

X.Litkium Cavlronate. .^f^J-ams 

DLiiillad \A/aiey /oocc 

Pvel,aV€ the daj^ before usin(^ 

ypotaiSlum P«vman§anafc- OS^vm. 

Oi&tilUd \MQiQY ioozc 

Matf le kijyt in stock 

V- oMalic accd, li^tam 

poiai$LU\n Sulftfiitq l^vam 

OL&.iitUd watev -- ioocc 

pvc/>avc the clay IrCjove asing 

H^mafeiirt oS^ram 

AlrtoLute alcohol ifcc 

PotoS/i alum J^gViawjS 

oiiiiiUd \Aiattr .,,., Sqocc 



Disio(v4 the hemckto)i.tfLin in tht alsclute 

alcohol and ihe alum ihthts/ijatcr- 
Mi'i^thi two Solutions And ddd the. 
^tjfCdirini. Fili^Y and exjaosc to li^ht 
and air fov &i.yival \ik/iek6 oy until 
the odo> ©f <j(co/io< ts ^one. Filter a 
S econd time.' If nuclei Are io iri Iryou^hf 
out U&eih.€ ixcididatid alcohol alroy^. 



Dissoi\/Q the h£mato%j/iit) intht 
air&olut^ alcohol, add the al^m-plsfcmnt 
Ynittay^ awd aC^tic acid^exjiose to air 
awd U^ht for a /oni^ tiwcor untU it 

is a d€cj>, Y^d color 



Haf£(«n th« tissues in fAiiliayS Fluid. 

Soak th« sections Scyerat hours in 1% 

ao'Sol-Chvomic acid. 

%tain foy l^ houy& in Soi. f. 

\/vash in watef conta/mn^ icc ioloocc 

of SoM 

DiffinniiaU in So/. 3. lio SniinutiS 

OccoUrize. in Sol ^■ 

wash in Water- iieh^drate,, Mount. 



oissoUeiheftematein inihi absolute alcohol 
^ith th9 aid of Heat. Dtssoive the alum in 
tK< v^aiey. Mit. the two ^oiutiom- 
FilUr. Add a crjst<i< gf thjftnol 



139 



i Statrii 









P^gj 



•gft'on Q-f koyrrroi t>s%u.q& 



rorrnala* 



Wc mafolj^tin . fttam 

Absolute cLcGkoi . /occ 

OiSiiUed v^at^Y 90cc 



D/fgc6'oT1<- 



/. /oK(i/?.soi. ferric Chloride. 

1./% 4if. So/. Hemafotyltn. 

sJ'ffo cf. So/. FetYi'c chloride-. _ 



in an t^tn v«S5«.(^w*«k5 Qnc{ ^i^oyt. 
Uiln^ diiuii \A/ith an ^f^uat vofam«cf 
water, rixikt Siciions'xYhouYi iti 
Z^T^ki'r.VjQih X^fiQUYS in fanning 

alcohols. Fix sections or^±he SiidQ 
q,vxi ilvTn&YSe in a X.S,« iro^-a/um 
Solution Hio^kouYS. Rtn^c it? water, 
gfetn in t'ni hernatoXylin Solution i3,to 
X^kours-kLniz in wat«>»anc/ fc^oce 
ad&in ir>iht iVo^i alum ioiution until 
i^iack cloud* ClaSi ioayisi. Dihfdrai^. 



Wix S««ldail$ onthi Slidi.^tain in 
(/)f.nr£f ro-f/vc Yninities. Blot. Pour 

ynado.. AIlo'^j M? s/<3.'>? fo yerndtn 3-S 
yninuii&.V4QSh. Dif-feyeriHote iri(i) 
V^aSh. Dthydrote . dear in ol ori^o-num. 



, .^ J HemaioXyliYt l^tatn- 

'f^'''i'^''f^iAho[uU alcohol _ /occ 

WematoXy/^n j^^ O^. So/, aa^iic acid lOQCc 



II. Eostn 



EoSin UoiakohoL) _ , . I^ratn 

Alcohol fSy% /MCc 



/^Si[vey... 



oiiiiiUd VJaier, 



l^ram 
/oocc 



/iosmic^ctf^ 



osmic Acid . 

Di&itiUd watey. 



/oocc 



D(SSo(v? t/i€ hematoxyLin m the 
aicohoL.Add the aceiic acid Solution 
X'aLaalrU in itciriin^ ney>/ous tissue. 



StoiMS Cjf'tolylQStn.A^I>lt)Xioihrinutt6- 



Wash ^vcshi/ssues in diiiiUed Wafer. 
imTncrS« thiVn in the iilwsr Solution S 
mthtxfiS. Kinsc in disti^Ud wafer and 
.exjbos^ to kri^hi S>iir.liqht in wotsy, 
alcohol or ^(jfCirin^. Mount in 
i;iL^CQyine or dry ihtm on th« Sh"d€" 
and mouyit in fa(sa>n . Th» si<v«y 
iS de|)05ifed in th€ Csmsnt. 



P(ac« th< sciatic h«pv« Of a Cat iniht 
OSmiC acid ^oLuiion for cdaj oy 
two Wash and Ki.<tj> in ?ofo alcohol 
until "heeded. Staihs fof ^^ack- 



140 



SoiA.JMuHeYS Fluid 3 VoCs 

|OSm<C/»C(<y Ifo SoL.a^. /vo( 

So/.B„ JS4^vcr hiiyoiU l^tam ^ 

\0UiUlQd SNckUt, ISocc 

I sUver /ritrati Iprom 

SotC'-^oisiitUd Wattr /5~occ 

ro»-mic Acid /-idw/s 



Tissues 



-StaiDi. 



-D/f.g.ct/on^- 






/SCoX'Sol^i 
Stain- 



SoiA.5f<>aa,So(- Potass. B ic ho tn- -• 

^oi Q.Sr^ Q^SolYneYCuYlC Qich/or.. 

$oiC. SZqo. So/, potass. Clivom.- 

oi$tHUd SNaidY. 

in stock ant/ VntKcd in ihi 
aloy/i jiYo^oviions whan u^ed- 



yocc 
•31 cc 



lLZhYiich'% 



Biood 



iOVan^iCt &at(m.$Ql /JOcc 

3 AcfW Fuchsin Sai-Qo. So/ .. .. lOQCc 

SMdhjfiQyeen iata^.Soi liScc 

^ Disiill<id v\iotcY ioocc] 

S.AlcohoL - Xoocc 

LCiiiiC<iYine loocc 



f/.\fi/ti^hi\ 
BloQifiiQin 



t.iodium BicaY^ohateO'Sfi a^ Sot. 
1 Methylene Blm /■% aq So/. 
^■toiix\itiiUo\N.%(iliwviaU\)o.l%oo Sot. 
¥.Mtihsi Alcohot 



p(qc« small fiks:4£- of HiYS/ous tissue in 
So^ A one io «i^hi dat)6,-then tvajisfcv 
to Soi-B ^otyxhouY in±hi c/avk.thcn 
to Sol.C ^oY A^ hoUYs OY tnoY«,ihen io 
9C% alcohol ^xh.oUY.Th<i S€ction& qyc 
tnounted in Xjfiol Bolsam \N^ich is 
alloyvedto dvif on t^« s/ic/cjno Covcv 
^laS$ is USid. 

P(actf fimo// Cules oj irvain av\d CcYd 
in lotoXo \/Qlum<is o^ the ^oYe^oin^ 
Soiution for ito to\Neeks chaYi^inb 
thetn a&^oLtoy^s: ^ihour6,5da^s, 
^dQj^$,tS(iatfS,J.ldaif$, SodajS. Trati&jn 
to 9Sf0 alcohol IhbUY, alcohol and 
eth<lY CQUoH>aYti ^AhouY.CUloidih I 
/loar, mount oh <x Uoc^yCleaY in X^jlol |, 
Cav^olic acid //.avt^in vvhtc/i thetf 
maj^ /< kej>t f Of weeks. Cuiyinouni 
on slide^covVi* with cos/ey ^iaiS- 

Mix //-Zj y, 5" ftn</ add S/ovv/i/ J[, 4. 
rii t^c f »/mS fi/ heai oy in daaat JsqyH 
oj alcohol and ethcY. 
Statin 3to /O n^iniiti^- 
\Na$h in Watcir 

DYjf in ait 

Mount. Red Uood cells nYe ^YickYid^ 
alt nuclei Ui^fit pY€en,iosinoj>hHis juchsin 
yed, neuivolihiles \iiolH ved. 

MiXMMi in a^laiiiaiidSteam Ihour in o 
&teYiliz^Y.\/^h«nCotd ftouY into lAY^dii.h. 
To foocc addSoocc ofii). UiY until tht 
Solution is j>uYf>U,SCum ^cito\M,\nita(lic, 
jiYicifiitati Irlack.ColUct f»Yicif,itatQ and 
dYy it. TO /oocc of(f)add0.3^vatn of-th9 
^Yecijtitaie. Fiitev. to ftOCc of thi 
-fi/tvatc add 20CC of Ineth^l alcohol 
TO itain: QYjf film i n aiy.A\>fly stain 
ItninuU addin^^dYof, Ir'f dYoji^y/vaiey 
until itain is S€niitYani/,ovent'2)ninai(%. 
V/oih. DYn- mount. Red CtlU. OVtt n$«, nucUi 
ylue,eoiino\>hihi Yid,ntutYohhiU^ 
litac. l-aiO^hiUi Irlui Uacti . 



141 



PYikiCxYCition of hormoL Tissues 



Sto L n s 



Form u tog 



/# EoS'riomlj Caustic Zodo golufion. 
H(th^ a / II c re w d to^% of Sat a^. &W. tnethji Blue 
it)l'/6C00 Caustic io^a SmiittioXi 



&LT\r.hioi\^. 



ffEoiinontt 
klethyf Blot 



i.0 Eostn »nd 
kcih^i Blut. 



2/- Tenner's 

BfMCf Staid 



$atCik9h§ik So/. EhrliCh^ Hood eoSth 
^qI.oo. sol Ehyrlich'i Mcih^l Bkie 
or\€ Wf<rk olH 

&aia» SfOl.^ethgl BLue Hcc 

iU% &*/.COSiii in7Sfc alcohol -Locc 

' Otifillcd vwoter. '^^cc 

Mix 

Hnn^iens Hftn'atoijf liri 
i.f«So/eos<rt imcTe alcchol 

TCnnev's S£oo<i &fa.zn 
Best procured ^roin tnunaj^dureri 



Piac€ the fi'trr\,^ii.edir\ tnerci^YiC 

mntu ve Sm i n utcs and in the 
Tnithi(l Blii€ )ni%ttite Ainirxuits 
\s/ash. Ofj. Mount- 

Piace ^dm in eoiin ioiutccn a^ew 
Scconc^S;W£i5>i,arW^/acc in hieihjl 
Bitif Solution Iminufi.v^osh enc/ 
yiffCai asneceu&r^. Or^ Tnount 

I Piact ^dm in the tniiture Sio S 
Itninttiei.y/vash D»^ Mount 

pioc€ -flint in ti^ kematott^lin Sto It 
ininutesv^ash PUct intAr CQUn ioi 1 
hitnuies.vvAS^- Dir^- Mount- 

\PLfiCt Siltn intht gtattf itfilittttei^^Mia^Sth. 
I Dr^ Mount 



= 



^joo^ smeovt- 



i.Cut itri^i ojCi^areiU jfohtr atiHLe nai-rcwc*- i^an o i/i^f/i^ww ohf cn^/ oft/»c 
^ol>f> through ctdrc^ of HOod ond olon^ th( ^uY{{iCi o^SkCl(Cxn Stcde Fix- 
LpUc€ a droh ofUcad uh-on o Cleati iUdt fi€ar ottt itid Qhd d^&w tbi Chei td^t of- 
anothtr ilidi through the drc^ oCon^t^e S<rK^c€. rlx 

' "' rof, of Uood u^on a cover g/aS& and anothfY Cover ^/oss itf>«n r"" " ' 

^►t v^iihoLit ^Yesiute Fit Jn af< Cases th< o/|>tt ts t© $ccare o tA 



Phe^fl»*otioh 
Oj Blood imec^ 



Htihodi 



3. P/oce o <i 

even /^o^ct* ofll«od 



ttf>cn it Stidf 



f. Place film in Sot a* ^^l-fnercuric BichUride /ntinutt.^A&tt. Dtf inair. 
l.Ploce film in an ovtn oi US'c for 10 minates. 

3 Poii Cover b/aS&^iVni thycu^h Btty^ifn fiamt until i*c hdt for tkeim.ndJfHJ^inttt 
^.Hiat Uide film iiO'-Uo'C. f tnintfU. 

S- Place film in ^^ual^rU tf alcohol tind€tktriOtntniitti.. Drj m air 
' iPiacefilm in Tormiline Iccto Urong alcohol ^00 cc- for S tnintiin Drj/ imair 
TpLicc film LnfS/t alcokol SOTninutei. D\^ in aiY. 
I PUci filtn in txlXoi^. UlChyofnic Acid f'jhiinate-Vtiaik Dry in atr 
tBXI^ose iiim tc \fcj30r oj osmic dctd Iminut^s,. 
ft.Ex^oit filnr to \ia^oy of FoYmcUnc 5 friinutti- 
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145 



PART II 

A CASE OF MODELS WITH ARCHITECTIVE OUTLINES FOR 

THE CONSTRUCTION OF ORGANS ACCORDING 

TO THE CONSTRUCTIVE METHOD 



INDEX TO TEXT. 



Achromatin, H 

Adrenals, 125 

Anaphases — chromatic changes, 19 

Anaphases — achromatic changes, 19 

Amitosis, 16 

Arrangement of tubes in five classes, 61 

Attraction sphere, 9 

B 
Binary fission, 16 
Brain, 111 
Budding, 18 

C 

Case outlines, 62 

Cause of cell division, 13 

Cell — a chemical and mechanical unit, 7 

Cell division, 12 

Cell membrane, 7 

Centrosome, 9 

Chromatin, 10 

Coat and layer defined, 50 

Coats and layers on curved lines, 52 

Conclusions drawn from the constructive 
diagram, 127-128 

Connective tissue coat, 95 

Constructive diagram, 126 

Contents of tubes govern their motor struc- 
tures, 108 

Cutting, 133 



Decalcification, 132 
Dehydration, 133 



D 



E 



Evolution of systems, 22 
Embedding, 133 , 

Epithelial coat, 96 
Epithelium essential to tubes, 98 
Eye ball, 88 

F 

Five classes of tubes, 61 
Fixing, 132 

11 



Formation of tubes, 49 
Four coated tubes — muscular — ^motor, 95 
Framework essential to tubes, 97 
Function of one layer tubes, 70 
Function of one coated tubes, 74 
Function of two coated tubes, 80 
Function of three coated tubes, 82 
Function of four coated tubes, 97 

G 

General outline of body, 3 
General formula of construction, 61 
General survey of the body, 125 
Gemmation, 18 



H 



Hardening, 132 
Hyaloplasm, 8 

Infiltration, 133 

Karyokinesis, 15 
Karyomitosis, 15 
Killing, 132 

Linin, 11 
Lymph Node, 122 



K 



M 



Mechanics, 64 

Metaplasm, 10 

Metaphases — chromatic changes, 18 

Metaphases — achromatic changes, 19 

Motor apparatus a necessity, 98 

Mounting, 134 

Muscular coat, 95 

N 
Net-knots, 11 

Non-motor and motor tubes, 64 
Nucleus, 10 
Nuclear membrane, 10 
Nucleolus, 11 


One layer tubes—non-motor, 69 
One coated ti^bes, 72 



149 



150 



INDEX TO TEXT. 



Organs of three coated tubes, 82 
Organs which do not conform to the tube 
plan of structure, 111 



Plan of tube arrangement, 48 
Plastids, 9 

Preparation of normal tissues, 131 
Prophases — chromatic changes, 18 
Prophases — achromatic changes, 18 

R 

Retrogressive changes, 19 

S 



Spleen, 122 

Spore formation, 18 



Spongioplasm, 8 
Stages of Karyokinesis, 18 
Subepithelial coat, 96 
Staining, 133 

T 

Telophases — chromatic changes, 19 

Telophases — achromatic changes, 19 

Tissues, 22 

Tissues as building materials, 97 

Three coated tubes, 81 

Tubes as structural and functional units, 47 

Two coated tubes, 80 

Thymus, 122 

V 

Vacuoles, 9 

Varieties of cell division, 14 



INDEX TO OUTLINES. 



Animal body, 4, 5 
Adipose tissue. 32 
Adrenals, 120 
Areolar tissue, 30 



B 



Blood, 38 

Blood smears, 142 

Blood fixing methods, 142 

Bone, 34 

Bone formation, 37 

C 

Carotid gland, 120 

Cartilage, 32 

Cerebrum, 112, 113 

Cerebellum, 117 

Clearing agents, 143 

Coccygeal gland, 120 

Connective tissue cells — special, 28 

Crura Cerebri, 114 



Decalcification, 136 
Dehydration, 136 



D 



E 



Ear — external, middle, 75 
Ear — internal, 76, 77 
Embedding, 137 
Epithelial cells, special, 2G 
Epithelial tissues, 24 
Eye ball, 89 

F 

Five circulations, 101 
Fixing formulae, 135 
Fixing sections to slide, 138 
Functions of tissues, 108 



Genesis of the tissue, 21 



H 

Hardening formulae, 135 



Infiltration, 133 
Iris, 90 



Locations of tissues, 107 
Lymphatic system, 102 
Lymphoid tissue, 30 



M 
Marrow, 37 

Medulla Oblongata, 115, 116 
Microscope, 144 

Models numbered and described, 60, 61 
Motor and non-motor tubes, 67 
Mucous tissue, 30 
Muscular tissue, 40 

N 
Nerve terminations, 44 
Nervous tissue, 42 
Neuroglia, 32 



O 



Olfactory lobe, 119 



Pineal Gland, 119 
Pituitary Body, 119 
Pons Varolii, 114 
Preserving sections, 138 



R 



Retina, 91 

Retinal divisions, 92 

Retiform tissue, 30 



151 



152 



INDEX TO OUTLINE. 



S 



Tonsils, 120 



Sex as an abridgment of solar agencies, 14 I'ube formations, 62 



Spinal cord, 118 

Spleen, 120 

Staining formulae, 138, 139, 140, 141, 142 



Thymus, 120 

W 
White fibrous tissue, 30 



Table of tubular constructions, 68, 69 

Teeth, 36 

Three tissues seen in tubes, 99, 100 



Yellow elastic tissue, 30 



FEB 20 1907 



